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AngularJS
Notes for Professionals
AngularJS
Notes for Professionals
100+ pages
of professional hints and tricks
GoalKicker.com
Free Programming Books
Disclaimer
This is an unocial free book created for educational purposes and is
not aliated with ocial AngularJS group(s) or company(s).
All trademarks and registered trademarks are
the property of their respective owners
Contents
About
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1
Chapter 1: Getting started with AngularJS
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2
Section 1.1: Getting Started
Section 1.2: Showcasing all common Angular constructs
Section 1.3: The importance of scope
Section 1.4: Minification in Angular
Section 1.5: AngularJS Getting Started Video Tutorials
Section 1.6: The Simplest Possible Angular Hello World
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Chapter 2: Modules
Section 2.1: Modules
Section 2.2: Modules
Chapter 3: Components
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Section 3.1: Basic Components and LifeCycle Hooks
Section 3.2: Components In angular JS
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Chapter 4: Built-in directives
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Section 4.1: Angular expressions - Text vs. Number
Section 4.2: ngIf
Section 4.3: ngCloak
Section 4.4: ngRepeat
Section 4.5: Built-In Directives Cheat Sheet
Section 4.6: ngInclude
Section 4.7: ng-model-options
Section 4.8: ngCopy
Section 4.9: ngPaste
Section 4.10: ngClick
Section 4.11: ngList
Section 4.12: ngOptions
Section 4.13: ngSrc
Section 4.14: ngModel
Section 4.15: ngClass
Section 4.16: ngDblclick
Section 4.17: ngHref
Section 4.18: ngPattern
Section 4.19: ngShow and ngHide
Section 4.20: ngRequired
Section 4.21: ngMouseenter and ngMouseleave
Section 4.22: ngDisabled
Section 4.23: ngValue
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Chapter 5: Use of in-built directives
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Section 5.1: Hide/Show HTML Elements
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Chapter 6: Custom Directives
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Section 6.1: Creating and consuming custom directives
Section 6.2: Directive Definition Object Template
Section 6.3: How to create resuable component using directive
Section 6.4: Basic Directive example
Section 6.5: Directive decorator
Section 6.6: Basic directive with template and an isolated scope
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Section 6.7: Building a reusable component
Section 6.8: Directive inheritance and interoperability
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Chapter 7: How data binding works
Section 7.1: Data Binding Example
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Chapter 8: Angular Project - Directory Structure
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Section 8.1: Directory Structure
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Chapter 9: Filters
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Section 9.1: Accessing a filtered list from outside an ng-repeat
Section 9.2: Custom filter to remove values
Section 9.3: Custom filter to format values
Section 9.4: Using filters in a controller or service
Section 9.5: Performing filter in a child array
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Chapter 10: Custom filters
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Section 10.1: Use a filter in a controller, a service or a filter
Section 10.2: Create a filter with parameters
Section 10.3: Simple filter example
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Chapter 11: Constants
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Section 11.1: Create your first constant
Section 11.2: Use cases
Chapter 12: Custom filters with ES6
Section 12.1: FileSize Filter using ES6
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Chapter 13: Directives using ngModelController
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Section 13.1: A simple control: rating
Section 13.2: A couple of complex controls: edit a full object
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Chapter 14: Controllers
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Section 14.1: Your First Controller
Section 14.2: Creating Controllers, Minification safe
Section 14.3: Using ControllerAs in Angular JS
Section 14.4: Creating Minification-Safe Angular Controllers
Section 14.5: Creating Controllers
Section 14.6: Nested Controllers
Chapter 15: Controllers with ES6
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Section 15.1: Controller
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Chapter 16: The Self Or This Variable In A Controller
Section 16.1: Understanding The Purpose Of The Self Variable
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Chapter 17: Services
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Section 17.1: Creating a service using angular.factory
Section 17.2: Dierence between Service and Factory
Section 17.3: $sce - sanitize and render content and resources in templates
Section 17.4: How to create a Service
Section 17.5: How to use a service
Section 17.6: How to create a Service with dependencies using 'array syntax'
Section 17.7: Registering a Service
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Chapter 18: Distinguishing Service vs Factory
Section 18.1: Factory VS Service once-and-for-all
Chapter 19: Angular promises with $q service
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Section 19.1: Wrap simple value into a promise using $q.when()
Section 19.2: Using angular promises with $q service
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Section 19.3: Using the $q constructor to create promises
Section 19.4: Avoid the $q Deferred Anti-Pattern
Section 19.5: Using $q.all to handle multiple promises
Section 19.6: Deferring operations using $q.defer
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Chapter 20: Dependency Injection
Section 20.1: Dynamic Injections
Section 20.2: Dynamically load AngularJS service in vanilla JavaScript
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Chapter 21: Events
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Section 21.1: Using angular event system
Section 21.2: Always deregister $rootScope.$on listeners on the scope $destory event
Section 21.3: Uses and significance
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Chapter 22: Sharing Data
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Section 22.1: Using ngStorage to share data
Section 22.2: Sharing data from one controller to another using service
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Chapter 23: Form Validation
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Section 23.1: Form and Input States
Section 23.2: CSS Classes
Section 23.3: Basic Form Validation
Section 23.4: Custom Form Validation
Section 23.5: Async validators
Section 23.6: ngMessages
Section 23.7: Nested Forms
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Chapter 24: Routing using ngRoute
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Section 24.1: Basic example
Section 24.2: Defining custom behavior for individual routes
Section 24.3: Route parameters example
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Chapter 25: ng-class directive
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Section 25.1: Three types of ng-class expressions
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Chapter 26: ng-repeat
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Section 26.1: ng-repeat-start + ng-repeat-end
Section 26.2: Iterating over object properties
Section 26.3: Tracking and Duplicates
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Chapter 27: ng-style
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Section 27.1: Use of ng-style
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Chapter 28: ng-view
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Section 28.1: Registration navigation
Section 28.2: ng-view
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Chapter 29: AngularJS bindings options (`=`, `@`, `&` etc.)
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Section 29.1: Bind optional attribute
Section 29.2: @ one-way binding, attribute binding
Section 29.3: = two-way binding
Section 29.4: & function binding, expression binding
Section 29.5: Available binding through a simple sample
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Chapter 30: Providers
Section 30.1: Provider
Section 30.2: Factory
Section 30.3: Constant
Section 30.4: Service
Section 30.5: Value
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Chapter 31: Decorators
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Section 31.1: Decorate service, factory
Section 31.2: Decorate directive
Section 31.3: Decorate filter
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Chapter 32: Print
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Section 32.1: Print Service
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Chapter 33: ui-router
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Section 33.1: Basic Example
Section 33.2: Multiple Views
Section 33.3: Using resolve functions to load data
Section 33.4: Nested Views / States
Chapter 34: Built-in helper Functions
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Section 34.1: angular.equals
Section 34.2: angular.toJson
Section 34.3: angular.copy
Section 34.4: angular.isString
Section 34.5: angular.isArray
Section 34.6: angular.merge
Section 34.7: angular.isDefined and angular.isUndefined
Section 34.8: angular.isDate
Section 34.9: angular.noop
Section 34.10: angular.isElement
Section 34.11: angular.isFunction
Section 34.12: angular.identity
Section 34.13: angular.forEach
Section 34.14: angular.isNumber
Section 34.15: angular.isObject
Section 34.16: angular.fromJson
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Chapter 35: digest loop walkthrough
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Section 35.1: $digest and $watch
Section 35.2: the $scope tree
Section 35.3: two way data binding
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Chapter 36: Angular $scopes
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Section 36.1: A function available in the entire app
Section 36.2: Avoid inheriting primitive values
Section 36.3: Basic Example of $scope inheritance
Section 36.4: How can you limit the scope on a directive and why would you do this?
Section 36.5: Using $scope functions
Section 36.6: Creating custom $scope events
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Chapter 37: Using AngularJS with TypeScript
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Section 37.1: Using Bundling / Minification
Section 37.2: Angular Controllers in Typescript
Section 37.3: Using the Controller with ControllerAs Syntax
Section 37.4: Why ControllerAs Syntax?
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Chapter 38: $http request
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Section 38.1: Timing of an $http request
Section 38.2: Using $http inside a controller
Section 38.3: Using $http request in a service
Chapter 39: Prepare for Production - Grunt
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Section 39.1: View preloading
Section 39.2: Script optimisation
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Chapter 40: Grunt tasks
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Section 40.1: Run application locally
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Chapter 41: Lazy loading
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Section 41.1: Preparing your project for lazy loading
Section 41.2: Usage
Section 41.3: Usage with router
Section 41.4: Using dependency injection
Section 41.5: Using the directive
Chapter 42: HTTP Interceptor
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Section 42.1: Generic httpInterceptor step by step
Section 42.2: Getting Started
Section 42.3: Flash message on response using http interceptor
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Chapter 43: Session storage
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Section 43.1: Handling session storage through service using angularjs
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Chapter 44: Angular MVC
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Section 44.1: The Static View with controller
Section 44.2: Controller Function Definition
Section 44.3: Adding information to the model
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Chapter 45: SignalR with AngularJS
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Section 45.1: SignalR and AngularJS [ ChatProject ]
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Chapter 46: Migration to Angular 2+
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Section 46.1: Converting your AngularJS app into a componend-oriented structure
Section 46.2: Introducing Webpack and ES6 modules
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Chapter 47: AngularJS with data filter, pagination etc
Section 47.1: AngularJS display data with filter, pagination
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Chapter 48: Profiling and Performance
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Section 48.1: 7 Simple Performance Improvements
Section 48.2: Bind Once
Section 48.3: ng-if vs ng-show
Section 48.4: Watchers
Section 48.5: Always deregister listeners registered on other scopes other than the current scope
Section 48.6: Scope functions and filters
Section 48.7: Debounce Your Model
Chapter 49: Performance Profiling
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Section 49.1: All About Profiling
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Chapter 50: Debugging
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Section 50.1: Using ng-inspect chrome extension
Section 50.2: Getting the Scope of element
Section 50.3: Basic debugging in markup
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Chapter 51: Unit tests
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Section 51.1: Unit test a component (1.5+)
Section 51.2: Unit test a filter
Section 51.3: Unit test a service
Section 51.4: Unit test a controller
Section 51.5: Unit test a directive
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Chapter 52: AngularJS gotchas and traps
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Section 52.1: Things to do when using html5Mode
Section 52.2: Two-way data binding stops working
Section 52.3: 7 Deadly Sins of AngularJS
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Credits
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You may also like
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194
About
Please feel free to share this PDF with anyone for free,
latest version of this book can be downloaded from:
https://goalkicker.com/AngularJSBook
This AngularJS Notes for Professionals book is compiled from Stack Overflow
Documentation, the content is written by the beautiful people at Stack Overflow.
Text content is released under Creative Commons BY-SA, see credits at the end
of this book whom contributed to the various chapters. Images may be copyright
of their respective owners unless otherwise specified
This is an unofficial free book created for educational purposes and is not
affiliated with official AngularJS group(s) or company(s) nor Stack Overflow. All
trademarks and registered trademarks are the property of their respective
company owners
The information presented in this book is not guaranteed to be correct nor
accurate, use at your own risk
Please send feedback and corrections to web@petercv.com
GoalKicker.com – AngularJS Notes for Professionals
1
Chapter 1: Getting started with AngularJS
Version Release Date
1.6.5
1.6.4
1.6.3
1.6.2
1.5.11
1.6.1
1.5.10
1.6.0
2017-07-03
2017-03-31
2017-03-08
2017-02-07
2017-01-13
2016-12-23
2016-12-15
2016-12-08
1.6.0-rc.2
2016-11-24
1.5.9
2016-11-24
1.6.0-rc.1
2016-11-21
1.6.0-rc.0
2016-10-26
1.2.32
1.4.13
1.2.31
1.5.8
1.2.30
1.5.7
1.4.12
1.5.6
1.4.11
1.5.5
1.5.4
1.5.3
1.5.2
2016-10-11
2016-10-10
2016-10-10
2016-07-22
2016-07-21
2016-06-15
2016-06-15
2016-05-27
2016-05-27
2016-04-18
2016-04-14
2016-03-25
2016-03-19
1.4.10
2016-03-16
1.5.1
1.5.0
2016-03-16
2016-02-05
1.5.0-rc.2
2016-01-28
1.4.9
2016-01-21
1.5.0-rc.1
2016-01-16
1.5.0-rc.0
2015-12-09
1.4.8
2015-11-20
1.5.0-beta.2 2015-11-18
1.4.7
1.3.20
1.2.29
2015-09-30
2015-09-30
2015-09-30
1.5.0-beta.1 2015-09-30
1.5.0-beta.0 2015-09-17
1.4.6
1.3.19
1.4.5
2015-09-17
2015-09-17
2015-08-28
GoalKicker.com – AngularJS Notes for Professionals
2
1.3.18
2015-08-19
1.4.4
1.4.3
2015-08-13
2015-07-15
1.3.17
2015-07-07
1.4.2
1.4.1
1.3.16
1.4.0
2015-07-07
2015-06-16
2015-06-06
2015-05-27
1.4.0-rc.2
2015-05-12
1.4.0-rc.1
2015-04-24
1.4.0-rc.0
2015-04-10
1.3.15
2015-03-17
1.4.0-beta.6 2015-03-17
1.4.0-beta.5 2015-02-24
1.3.14
2015-02-24
1.4.0-beta.4 2015-02-09
1.3.13
1.3.12
2015-02-09
2015-02-03
1.4.0-beta.3 2015-02-03
1.3.11
2015-01-27
1.4.0-beta.2 2015-01-27
1.4.0-beta.1 2015-01-20
1.3.10
1.3.9
2015-01-20
2015-01-15
1.4.0-beta.0 2015-01-14
1.3.8
1.2.28
1.3.7
1.3.6
1.3.5
1.3.4
2014-12-19
2014-12-16
2014-12-15
2014-12-09
2014-12-02
2014-11-25
1.2.27
2014-11-21
1.3.3
1.3.2
1.3.1
1.3.0
2014-11-18
2014-11-07
2014-10-31
2014-10-14
1.3.0-rc.5
2014-10-09
1.2.26
2014-10-03
1.3.0-rc.4
2014-10-02
1.3.0-rc.3
2014-09-24
1.2.25
2014-09-17
1.3.0-rc.2
2014-09-17
1.2.24
2014-09-10
1.3.0-rc.1
2014-09-10
1.3.0-rc.0
2014-08-30
1.2.23
2014-08-23
GoalKicker.com – AngularJS Notes for Professionals
3
1.3.0-beta.19 2014-08-23
1.2.22
2014-08-12
1.3.0-beta.18 2014-08-12
1.2.21
2014-07-25
1.3.0-beta.17 2014-07-25
1.3.0-beta.16 2014-07-18
1.2.20
2014-07-11
1.3.0-beta.15 2014-07-11
1.2.19
2014-07-01
1.3.0-beta.14 2014-07-01
1.3.0-beta.13 2014-06-16
1.3.0-beta.12 2014-06-14
1.2.18
2014-06-14
1.3.0-beta.11 2014-06-06
1.2.17
2014-06-06
1.3.0-beta.10 2014-05-24
1.3.0-beta.9 2014-05-17
1.3.0-beta.8 2014-05-09
1.3.0-beta.7 2014-04-26
1.3.0-beta.6 2014-04-22
1.2.16
2014-04-04
1.3.0-beta.5 2014-04-04
1.3.0-beta.4 2014-03-28
1.2.15
2014-03-22
1.3.0-beta.3 2014-03-21
1.3.0-beta.2 2014-03-15
1.3.0-beta.1 2014-03-08
1.2.14
1.2.13
1.2.12
1.2.11
1.2.10
1.2.9
1.2.8
1.2.7
1.2.6
1.2.5
1.2.4
1.2.3
1.2.2
1.2.1
1.2.0
2014-03-01
2014-02-15
2014-02-08
2014-02-03
2014-01-25
2014-01-15
2014-01-10
2014-01-03
2013-12-20
2013-12-13
2013-12-06
2013-11-27
2013-11-22
2013-11-15
2013-11-08
1.2.0-rc.3
2013-10-14
1.2.0-rc.2
2013-09-04
1.0.8
2013-08-22
1.2.0rc1
2013-08-13
GoalKicker.com – AngularJS Notes for Professionals
4
1.0.7
1.1.5
1.0.6
1.1.4
1.0.5
1.1.3
1.0.4
1.1.2
1.1.1
1.0.3
1.1.0
1.0.2
1.0.1
1.0.0
2013-05-22
2013-05-22
2013-04-04
2013-04-04
2013-02-20
2013-02-20
2013-01-23
2013-01-23
2012-11-27
2012-11-27
2012-09-04
2012-09-04
2012-06-25
2012-06-14
v1.0.0rc12
2012-06-12
v1.0.0rc11
2012-06-11
v1.0.0rc10
2012-05-24
v1.0.0rc9
2012-05-15
v1.0.0rc8
2012-05-07
v1.0.0rc7
2012-05-01
v1.0.0rc6
2012-04-21
v1.0.0rc5
2012-04-12
v1.0.0rc4
2012-04-05
v1.0.0rc3
2012-03-30
v1.0.0rc2
2012-03-21
g3-v1.0.0rc1 2012-03-14
g3-v1.0.0-rc2 2012-03-16
1.0.0rc1
2012-03-14
0.10.6
0.10.5
0.10.4
0.10.3
0.10.2
0.10.1
0.10.0
0.9.19
0.9.18
0.9.17
0.9.16
0.9.15
0.9.14
0.9.13
0.9.12
0.9.11
0.9.10
0.9.9
2012-01-17
2011-11-08
2011-10-23
2011-10-14
2011-10-08
2011-09-09
2011-09-02
2011-08-21
2011-07-30
2011-06-30
2011-06-08
2011-04-12
2011-04-01
2011-03-14
2011-03-04
2011-02-09
2011-01-27
2011-01-14
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0.9.7
0.9.6
0.9.5
0.9.4
0.9.3
0.9.2
0.9.1
0.9.0
2010-12-11
2010-12-07
2010-11-25
2010-11-19
2010-11-11
2010-11-03
2010-10-27
2010-10-21
Section 1.1: Getting Started
Create a new HTML file and paste the following content:
<!DOCTYPE html>
<html ng-app>
<head>
 <title>Hello, Angular</title>
 <script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
</head>
<body ng-init="name='World'">
 <label>Name</label>
 <input ng-model="name" />
 <span>Hello, {{ name }}!</span>
 <p ng-bind="name"></p>
</body>
</html>
Live demo
When you open the file with a browser, you will see an input field followed by the text Hello, World!. Editing the
value in the input will update the text in real-time, without the need to refresh the whole page.
Explanation:
1.
Load the Angular framework from a Content Delivery Network.
<script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
2.
Define the HTML document as an Angular application with the ng-app directive
<html ng-app>
3.
Initialize the name variable using ng-init
<body ng-init=" name = 'World' ">
Note that ng-init should be used for demonstrative and testing purposes only. When building an actual application,
controllers should initialize the data.
4.
Bind data from the model to the view on HTML controls. Bind an <input> to the name property with ng-model
<input ng-model="name" />
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5.
Display content from the model using double braces {{ }}
<span>Hello, {{ name }}</span>
6.
Another way of binding the name property is using ng-bind instead of handlebars"{{ }}"
<span ng-bind="name"></span>
The last three steps establish the two way data-binding. Changes made to the input update the model, which is
reflected in the view.
There is a difference between using handlebars and ng-bind. If you use handlebars, you might see the actual
Hello, {{name}} as the page loads before the expression is resolved (before the data is loaded) whereas if you use
ng-bind, it will only show the data when the name is resolved. As an alternative the directive ng-cloak can be used
to prevent handlebars to display before it is compiled.
Section 1.2: Showcasing all common Angular constructs
The following example shows common AngularJS constructs in one file:
<!DOCTYPE html>
<html ng-app="myDemoApp">
 <head>
 <style>.started { background: gold; }</style>
 <script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
 <script>
 function MyDataService() {
 return {
 getWorlds: function getWorlds() {
 return ["this world", "another world"];
 }
 };
 }
function DemoController(worldsService) {
 var vm = this;
 vm.messages = worldsService.getWorlds().map(function(w) {
 return "Hello, " + w + "!";
 });
 }
function startup($rootScope, $window) {
 $window.alert("Hello, user! Loading worlds...");
 $rootScope.hasStarted = true;
 }
angular.module("myDemoApp", [/* module dependencies go here */])
 .service("worldsService", [MyDataService])
 .controller("demoController", ["worldsService", DemoController])
 .config(function() {
 console.log('configuring application');
 })
 .run(["$rootScope", "$window", startup]);
 </script>
 </head>
 <body ng-class="{ 'started': hasStarted }" ng-cloak>
 <div ng-controller="demoController as vm">
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<ul>
 <li ng-repeat="msg in vm.messages">{{ msg }}</li>
 </ul>
 </div>
 </body>
</html>
Every line of the file is explained below:
Live Demo
1.
ng-app="myDemoApp", the ngApp directive that bootstraps the application and tells angular that a DOM
element is controlled by a specific angular.module named "myDemoApp";
2.
<script src="angular.min.js"> is the first step in bootstrapping the AngularJS library;
Three functions (MyDataService, DemoController, and startup) are declared, which are used (and explained)
below.
3.
angular.module(...) used with an array as the second argument creates a new module. This array is used
to supply a list of module dependencies. In this example we chain calls on the result of the module(...)
function;
4.
.service(...) creates an Angular Service and returns the module for chaining;
5.
.controller(...) creates an Angular Controller and returns the module for chaining;
6.
.config(...) Use this method to register work which needs to be performed on module loading.
7.
.run(...) makes sure code is run at startup time and takes an array of items as a parameter. Use this
method to register work which should be performed when the injector is done loading all modules.
the first item is letting Angular know that the startup function requires the built-in $rootScope service
to be injected as an argument;
the second item is letting Angular know that the startup function requires the built-in $window service
to be injected as an argument;
the last item in the array, startup, is the actual function to run on startup;
8.
ng-class is the ngClass directive to set a dynamic class, and in this example utilizes hasStarted on the
$rootScope dynamically
9.
ng-cloak is a directive to prevent the unrendered Angular html template (e.g. "{{ msg }}") to be briefly
shown before Angular has fully loaded the application.
10.
ng-controller is the directive that asks Angular to instantiate a new controller of specific name to
orchestrate that part of the DOM;
11.
ng-repeat is the directive to make Angular iterate over a collection and clone a DOM template for each item;
12.
{{ msg }} showcases interpolation: on-the-spot rendering of a part of the scope or controller;
Section 1.3: The importance of scope
As Angular uses HTML to extend a web page and plain Javascript to add logic, it makes it easy to create a web page
using ng-app, ng-controller and some built-in directives such as ng-if, ng-repeat, etc. With the new controllerAs
syntax, newcomers to Angular users can attach functions and data to their controller instead of using $scope.
However, sooner or later, it is important to understand what exactly this $scope thing is. It will keep showing up in
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examples so it is important to have some understanding.
The good news is that it is a simple yet powerful concept.
When you create the following:
<div ng-app="myApp">
 <h1>Hello {{ name }}</h1>
</div>
Where does name live?
The answer is that Angular creates a $rootScope object. This is simply a regular Javascript object and so name is a
property on the $rootScope object:
angular.module("myApp", [])
 .run(function($rootScope) {
 $rootScope.name = "World!";
 });
And just as with global scope in Javascript, it's usually not such a good idea to add items to the global scope or
$rootScope.
Of course, most of the time, we create a controller and put our required functionality into that controller. But when
we create a controller, Angular does it's magic and creates a $scope object for that controller. This is sometimes
referred to as the local scope.
So, creating the following controller:
<div ng-app="myApp">
 <div ng-controller="MyController">
 <h1>Hello {{ name }}</h1>
 </div>
</div>
would allow the local scope to be accessible via the $scope parameter.
angular.module("myApp", [])
 .controller("MyController", function($scope) {
 $scope.name = "Mr Local!";
 });
A controller without a $scope parameter may simply not need it for some reason. But it is important to realize that,
even with controllerAs syntax, the local scope exists.
As $scope is a JavaScript object, Angular magically sets it up to prototypically inherit from $rootScope. And as you
can imagine, there can be a chain of scopes. For example, you could create a model in a parent controller and
attach to it to the parent controller's scope as $scope.model.
Then via the prototype chain, a child controller could access that same model locally with $scope.model.
None of this is initially evident, as it's just Angular doing its magic in the background. But understanding $scope is
an important step in getting to know how Angular works.
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Section 1.4: Minification in Angular
What is Minification ?
It is the process of removing all unnecessary characters from source code without changing its functionality.
Normal Syntax
If we use normal angular syntax for writing a controller then after minifiying our files it going to break our
functionality.
Controller (Before minification) :
var app = angular.module('mainApp', []);
app.controller('FirstController', function($scope) {
 $scope.name= 'Hello World !';
});
After using minification tool, It will be minified as like below.
var app=angular.module("mainApp",[]);app.controller("FirstController",function(e){e.name= 'Hello
World !'})
Here, minification removed unnecessary spaces and the $scope variable from code. So when we use this minified
code then its not going to print anything on view. Because $scope is a crucial part between controller and view,
which is now replaced by the small 'e' variable. So when you run the application it is going to give Unknown
Provider 'e' dependency error.
There are two ways of annotating your code with service name information which are minification safe:
Inline Annotation Syntax
var app = angular.module('mainApp', []);
app.controller('FirstController', ['$scope', function($scope) {
 $scope.message = 'Hello World !';
}]);
$inject Property Annotation Syntax
FirstController.$inject = ['$scope'];
var FirstController = function($scope) {
 $scope.message = 'Hello World !';
}
var app = angular.module('mainApp', []);
app.controller('FirstController', FirstController);
After minification, this code will be
var
app=angular.module("mainApp",[]);app.controller("FirstController",["$scope",function(a){a.message="
Hello World !"}]);
Here, angular will consider variable 'a' to be treated as $scope, and It will display output as 'Hello World !'.
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Section 1.5: AngularJS Getting Started Video Tutorials
There are a lot of good video tutorials for the AngularJS framework on egghead.io
https://egghead.io/courses/angularjs-app-from-scratch-getting-started
https://egghead.io/courses/angularjs-application-architecture
https://egghead.io/courses/angular-material-introduction
https://egghead.io/courses/building-an-angular-1-x-ionic-application
https://egghead.io/courses/angular-and-webpack-for-modular-applications
https://egghead.io/courses/angularjs-authentication-with-jwt
https://egghead.io/courses/angularjs-data-modeling
https://egghead.io/courses/angular-automation-with-gulp
https://egghead.io/courses/learn-protractor-testing-for-angularjs
https://egghead.io/courses/ionic-quickstart-for-windows
https://egghead.io/courses/build-angular-1-x-apps-with-redux
https://egghead.io/courses/using-angular-2-patterns-in-angular-1-x-apps
Section 1.6: The Simplest Possible Angular Hello World
Angular 1 is at heart a DOM compiler. We can pass it HTML, either as a template or just as a regular web page, and
then have it compile an app.
We can tell Angular to treat a region of the page as an expression using the {{ }} handlebars style syntax. Anything
between the curly braces will be compiled, like so:
{{ 'Hello' + 'World' }}
This will output:
HelloWorld
ng-app
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We tell Angular which portion of our DOM to treat as the master template using the ng-app directive. A directive is a
custom attribute or element that the Angular template compiler knows how to deal with. Let's add an ng-app
directive now:
<html>
 <head>
 <script src="/angular.js"></script>
 </head>
 <body ng-app>
 {{ 'Hello' + 'World' }}
 </body>
</html>
I've now told the body element to be the root template. Anything in it will be compiled.
Directives
Directives are compiler directives. They extend the capabilities of the Angular DOM compiler. This is why Misko, the
creator of Angular, describes Angular as:
"What a web browser would have been had it been built for web applications.
We literally create new HTML attributes and elements, and have Angular compile them into an app. ng-app is a
directive that simply turns on the compiler. Other directives include:
ng-click, which adds a click handler,
ng-hide, which conditionally hides an element, and
<form>, which adds additional behaviour to a standard HTML form element.
Angular comes with around 100 built-in directives which allow you to accomplish most common tasks. We can also
write our own, and these will be treated in the same way as the built in directives.
We build an Angular app out of a series of directives, wired together with HTML.
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Chapter 2: Modules
Section 2.1: Modules
Module serves as a container of different parts of your app such as controllers, services, filters, directives, etc.
Modules can be referenced by other modules through Angular's dependency injection mechanism.
Creating a module:
angular
 .module('app', []);
Array [] passed in above example is the list of modules app depends on, if there are no dependencies then we pass
Empty Array i.e. [].
Injecting a module as a dependency of another module:
angular.module('app', [
 'app.auth',
 'app.dashboard'
]);
Referencing a module:
angular
 .module('app');
Section 2.2: Modules
Module is a container for various parts of your applications - controller, services, filters, directive, etc.
Why to use Modules
Most applications have a main method that instantiates and wires together the different parts of the application.
Angular apps don't have main method.
But in AngularJS the declarative process is easy to understand and one can package code as reusable modules.
Modules can be loaded in any order because modules delay execution.
declare a module
var app = angular.module('myApp', []);
// Empty array is list of modules myApp is depends on.
// if there are any required dependancies,
// then you can add in module, Like ['ngAnimate']
app.controller('myController', function() {
// write your business logic here
});
Module Loading and Dependencies
1.
Configuration Blocks: get executed during provider and configuration phase.
angular.module('myModule', []).
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config(function(injectables) {
 // here you can only inject providers in to config blocks.
});
2.
Run Blocks: get executed after the injector is created and are used to start the application.
angular.module('myModule', []).
run(function(injectables) {
 // here you can only inject instances in to config blocks.
});
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Chapter 3: Components
Parameter
Details
=
<
@
&
-
For using two-way data binding. This means that if you update that variable in your
component scope, the change will be reflected on the parent scope.
One-way bindings when we just want to read a value from a parent scope and not
update it.
String parameters.
For callbacks in case your component needs to output something to its parent scope.
-
LifeCycle Hooks
Details (requires angular.version >= 1.5.3 )
$onInit()
$onChanges(changesObj)
$onDestroy()
$postLink()
$doCheck()
Called on each controller after all the controllers on an element have been constructed
and had their bindings initialized. This is a good place to put initialization code for your
controller.
Called whenever one-way bindings are updated. The changesObj is a hash whose keys
are the names of the bound properties that have changed, and the values are an object
of the form { currentValue, previousValue, isFirstChange() } .
Called on a controller when its containing scope is destroyed. Use this hook for
releasing external resources, watches and event handlers.
Called after this controller’s element and its children have been linked. This hook can
be considered analogous to the ngAfterViewInit and ngAfterContentInit hooks in
Angular 2.
Called on each turn of the digest cycle. Provides an opportunity to detect and act on
changes. Any actions that you wish to take in response to the changes that you detect
must be invoked from this hook; implementing this has no effect on when $onChanges
is called.
Section 3.1: Basic Components and LifeCycle Hooks
What’s a component?
A component is basically a directive that uses a simpler configuration and that is suitable for a component-
based architecture, which is what Angular 2 is all about. Think of a component as a widget: A piece of HTML
code that you can reuse in several different places in your web application.
Component
angular.module('myApp', [])
 .component('helloWorld', {
 template: '<span>Hello World!</span>'
 });
Markup
<div ng-app="myApp">
 <hello-world> </hello-world>
</div>
Live Demo
Using External data in Component:
We could add a parameter to pass a name to our component, which would be used as follows:
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angular.module("myApp", [])
 .component("helloWorld",{
 template: '<span>Hello {{$ctrl.name}}!</span>',
 bindings: { name: '@' }
 });
Markup
<div ng-app="myApp">
 <hello-world name="'John'" > </hello-world>
</div>
Live Demo
Using Controllers in Components
Let’s take a look at how to add a controller to it.
angular.module("myApp", [])
 .component("helloWorld",{
 template: "Hello {{$ctrl.name}}, I'm {{$ctrl.myName}}!",
 bindings: { name: '@' },
 controller: function(){
 this.myName = 'Alain';
 }
 });
Markup
<div ng-app="myApp">
<hello-world name="John"> </hello-world>
</div>
CodePen Demo
Parameters passed to the component are available in the controller's scope just before its $onInit function gets
called by Angular. Consider this example:
angular.module("myApp", [])
 .component("helloWorld",{
 template: "Hello {{$ctrl.name}}, I'm {{$ctrl.myName}}!",
 bindings: { name: '@' },
 controller: function(){
 this.$onInit = function() {
 this.myName = "Mac" + this.name;
 }
 }
 });
In the template from above, this would render "Hello John, I'm MacJohn!".
Note that $ctrl is the Angular default value for controllerAs if one is not specified.
Live Demo
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Using “require” as an Object
In some instances you may need to access data from a parent component inside your component.
This can be achieved by specifying that our component requires that parent component, the require will give us
reference to the required component controller, which can then be used in our controller as shown in the example
below:
Notice that required controllers are guaranteed to be ready only after the $onInit hook.
angular.module("myApp", [])
 .component("helloWorld",{
 template: "Hello {{$ctrl.name}}, I'm {{$ctrl.myName}}!",
 bindings: { name: '@' },
 require: {
 parent: '^parentComponent'
 },
 controller: function () {
 // here this.parent might not be initiated yet
this.$onInit = function() {
 // after $onInit, use this.parent to access required controller
 this.parent.foo();
 }
}
 });
Keep in mind, though, that this creates a tight coupling between the child and the parent.
Section 3.2: Components In angular JS
The components in angularJS can be visualised as a custom directive (< html > this in an HTML directive, and
something like this will be a custom directive < ANYTHING >). A component contains a view and a controller.
Controller contains the business logic which is binded with an view , which the user sees. The component differs
from a angular directive because it contains less configuration. An angular component can be defined like this.
angular.module("myApp",[]).component("customer", {})
Components are defined on the angular modules. They contains two arguments, One is the name of the
component and second one is a object which contains key value pair, which defines which view and which
controller it is going to use like this .
angular.module("myApp",[]).component("customer", {
 templateUrl : "customer.html", // your view here
 controller: customerController, //your controller here
 controllerAs: "cust" //alternate name for your controller
})
"myApp" is the name of the app we are building and customer is the name of our component. Now for calling it in
main html file we will just put it like this
<customer></customer>
Now this directive will be replaced by the view you have specified and the business logic you have written in your
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controller.
NOTE : Remember component take a object as second argument while directive take a factory function as
argument.
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Chapter 4: Built-in directives
Section 4.1: Angular expressions - Text vs. Number
This example demonstrates how Angular expressions are evaluated when using type="text" and type="number"
for the input element. Consider the following controller and view:
Controller
var app = angular.module('app', []);
app.controller('ctrl', function($scope) {
 $scope.textInput = {
 value: '5'
 };
$scope.numberInput = {
 value: 5
 };
 });
View
<div ng-app="app" ng-controller="ctrl">
 <input type="text" ng-model="textInput.value">
 {{ textInput.value + 5 }}
 <input type="number" ng-model="numberInput.value">
 {{ numberInput.value + 5 }}
</div>
When using + in an expression bound to text input, the operator will concatenate the strings (first example),
displaying 55 on the screen*.
When using + in an expression bound to number input, the operator return the sum of the numbers (second
example), displaying 10 on the screen*.
* - That is until the user changes the value in the input field, afterward the display will change accordingly.
Working Example
Section 4.2: ngIf
ng-if is a directive similar to ng-show but inserts or removes the element from the DOM instead of simply hiding it.
Angular 1.1.5 introduced ng-If directive. You can Use ng-if directive above 1.1.5 versions. This is useful because
Angular will not process digests for elements inside a removed ng-if reducing the workload of Angular especially
for complex data bindings.
Unlike ng-show, the ng-if directive creates a child scope which uses prototypal inheritance. This means that setting
a primitive value on the child scope will not apply to the parent. To set a primitive on the parent scope the $parent
property on the child scope will have to be used.
JavaScript
angular.module('MyApp', []);
angular.module('MyApp').controller('myController', ['$scope', '$window', function
myController($scope, $window) {
 $scope.currentUser= $window.localStorage.getItem('userName');
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}]);
View
<div ng-controller="myController">
 <div ng-if="currentUser">
 Hello, {{currentUser}}
 </div>
 <div ng-if="!currentUser">
 <a href="/login">Log In</a>
 <a href="/register">Register</a>
 </div>
</div>
DOM If currentUser Is Not Undefined
<div ng-controller="myController">
 <div ng-if="currentUser">
 Hello, {{currentUser}}
 </div>
 <!-- ng-if: !currentUser -->
</div>
DOM If currentUser Is Undefined
<div ng-controller="myController">
 <!-- ng-if: currentUser -->
 <div ng-if="!currentUser">
 <a href="/login">Log In</a>
 <a href="/register">Register</a>
 </div>
</div>
Working Example
Function Promise
The ngIf directive accepts functions as well, which logically require to return true or false.
<div ng-if="myFunction()">
 <span>Span text</span>
</div>
The span text will only appear if the function returns true.
$scope.myFunction = function() {
 var result = false;
 // Code to determine the boolean value of result
 return result;
};
As any Angular expression the function accepts any kind of variables.
Section 4.3: ngCloak
The ngCloak directive is used to prevent the Angular html template from being briefly displayed by the
browser in its raw (uncompiled) form while your application is loading. - View source
HTML
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<div ng-cloak>
 <h1>Hello {{ name }}</h1>
</div>
ngCloak can be applied to the body element, but the preferred usage is to apply multiple ngCloak directives to
small portions of the page to permit progressive rendering of the browser view.
The ngCloak directive has no parameters.
See also: Preventing flickering
Section 4.4: ngRepeat
ng-repeat is a built in directive in Angular which lets you iterate an array or an object and gives you the ability to
repeat an element once for each item in the collection.
ng-repeat an array
<ul>
 <li ng-repeat="item in itemCollection">
 {{item.Name}}
 </li>
</ul>
Where:
item = individual item in the collection
itemCollection = The array you are iterating
ng-repeat an object
<ul>
 <li ng-repeat="(key, value) in myObject">
 {{key}} : {{value}}
 </li>
</ul>
Where:
key = the property name
value = the value of the property
myObject = the object you are iterating
filter your ng-repeat by user input
<input type="text" ng-model="searchText">
<ul>
 <li ng-repeat="string in stringArray | filter:searchText">
 {{string}}
 </li>
</ul>
Where:
searchText = the text that the user wants to filter the list by
stringArray = an array of strings, e.g. ['string', 'array']
You can also display or reference the filtered items elsewhere by assigning the filter output an alias with as
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aliasName, like so:
<input type="text" ng-model="searchText">
<ul>
 <li ng-repeat="string in stringArray | filter:searchText as filteredStrings">
 {{string}}
 </li>
</ul>
<p>There are {{filteredStrings.length}} matching results</p>
ng-repeat-start and ng-repeat-end
To repeat multiple DOM elements by defining a start and an end point you can use the ng-repeat-start and ng-
repeat-end directives.
<ul>
 <li ng-repeat-start="item in [{a: 1, b: 2}, {a: 3, b:4}]">
 {{item.a}}
 </li>
 <li ng-repeat-end>
 {{item.b}}
 </li>
</ul>
Output:
1
2
3
4
It is important to always close ng-repeat-start with ng-repeat-end.
Variables
ng-repeat also exposes these variables inside the expression
Variable Type
$index Number
Details
Equals to the index of the current iteration ($index===0 will evaluate to true at the first iterated
element; see $first)
$first Boolean Evaluates to true at the first iterated element
$last
Boolean Evaluates to true at the last iterated element
$middle Boolean Evaluates to true if the element is between the $first and $last
$even
Boolean Evaluates to true at an even numbered iteration (equivalent to $index%2===0)
$odd
Boolean Evaluates to true at an odd numbered iteration (equivalent to $index%2===1)
Performance considerations
Rendering ngRepeat can become slow, especially when using large collections.
If the objects in the collection have an identifier property, you should always track by the identifier instead of the
whole object, which is the default functionality. If no identifier is present, you can always use the built-in $index.
<div ng-repeat="item in itemCollection track by item.id">
<div ng-repeat="item in itemCollection track by $index">
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Scope of ngRepeat
ngRepeat will always create an isolated child scope so care must be taken if the parent scope needs to be accessed
inside the repeat.
Here is a simple example showing how you can set a value in your parent scope from a click event inside of
ngRepeat.
scope val: {{val}}<br/>
ctrlAs val: {{ctrl.val}}
<ul>
 <li ng-repeat="item in itemCollection">
 <a href="#" ng-click="$parent.val=item.value; ctrl.val=item.value;">
 {{item.label}} {{item.value}}
 </a>
 </li>
</ul>
$scope.val = 0;
this.val = 0;
$scope.itemCollection = [{
 id: 0,
 value: 4.99,
 label: 'Football'
},
{
 id: 1,
 value: 6.99,
 label: 'Baseball'
},
{
 id: 2,
 value: 9.99,
 label: 'Basketball'
}];
If there was only val = item.value at ng-click it won't update the val in the parent scope because of the isolated
scope. That's why the parent scope is accessed with $parent reference or with the controllerAs syntax (e.g. ng-
controller="mainController as ctrl").
Nested ng-repeat
You can also use nested ng-repeat.
<div ng-repeat="values in test">
 <div ng-repeat="i in values">
 [{{$parent.$index}},{{$index}}] {{i}}
 </div>
</div>
var app = angular.module("myApp", []);
app.controller("ctrl", function($scope) {
 $scope.test = [
 ['a', 'b', 'c'],
 ['d', 'e', 'f']
 ];
});
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Here to access the index of parent ng-repeat inside child ng-repeat, you can use $parent.$index.
Section 4.5: Built-In Directives Cheat Sheet
ng-app Sets the AngularJS section.
ng-init Sets a default variable value.
ng-bind Alternative to {{ }} template.
ng-bind-template Binds multiple expressions to the view.
ng-non-bindable States that the data isn't bindable.
ng-bind-html Binds inner HTML property of an HTML element.
ng-change Evaluates specified expression when the user changes the input.
ng-checked Sets the checkbox.
ng-class Sets the css class dynamically.
ng-cloak Prevents displaying the content until AngularJS has taken control.
ng-click Executes a method or expression when element is clicked.
ng-controller Attaches a controller class to the view.
ng-disabled Controls the form element's disabled property
ng-form Sets a form
ng-href Dynamically bind AngularJS variables to the href attribute.
ng-include Used to fetch, compile and include an external HTML fragment to your page.
ng-if Remove or recreates an element in the DOM depending on an expression
ng-switch Conditionally switch control based on matching expression.
ng-model Binds an input,select, textarea etc elements with model property.
ng-readonly Used to set readonly attribute to an element.
ng-repeat Used to loop through each item in a collection to create a new template.
ng-selected Used to set selected option in element.
ng-show/ng-hide Show/Hide elements based on an expression.
ng-src Dynamically bind AngularJS variables to the src attribute.
ng-submit Bind angular expressions to onsubmit events.
ng-value Bind angular expressions to the value of .
ng-required Bind angular expressions to onsubmit events.
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ng-style Sets CSS style on an HTML element.
ng-pattern Adds the pattern validator to ngModel.
ng-maxlength Adds the maxlength validator to ngModel.
ng-minlength Adds the minlength validator to ngModel.
ng-classeven Works in conjunction with ngRepeat and take effect only on odd (even) rows.
ng-classodd Works in conjunction with ngRepeat and take effect only on odd (even) rows.
ng-cut Used to specify custom behavior on cut event.
ng-copy Used to specify custom behavior on copy event.
ng-paste Used to specify custom behavior on paste event.
ng-options Used to dynamically generate a list of elements for the element.
ng-list Used to convert string into list based on specified delimiter.
ng-open Used to set the open attribute on the element, if the expression inside ngOpen is truthy.
Source (edited a bit)
Section 4.6: ngInclude
ng-include allows you to delegate the control of one part of the page to a specific controller. You may want to do
this because the complexity of that component is becoming such that you want to encapsulate all the logic in a
dedicated controller.
An example is:
<div ng-include
 src="'/gridview'"
 ng-controller='gridController as gc'>
 </div>
Note that the /gridview will need to be served by the web server as a distinct and legitimate url.
Also, note that the src-attribute accepts an Angular expression. This could be a variable or a function call for
example or, like in this example, a string constant. In this case you need to make sure to wrap the source URL in
single quotes, so it will be evaluated as a string constant. This is a common source of confusion.
Within the /gridview html, you can refer to the gridController as if it were wrapped around the page, eg:
<div class="row">
 <button type="button" class="btn btn-default" ng-click="gc.doSomething()"></button>
</div>
Section 4.7: ng-model-options
ng-model-options allows to change the default behavior of ng-model, this directive allows to register events that
will fire when the ng-model is updated and to attach a debounce effect.
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This directive accepts an expression that will evaluate to a definition object or a reference to a scope value.
Example:
<input type="text" ng-model="myValue" ng-model-options="{'debounce': 500}">
The above example will attach a debounce effect of 500 milliseconds on myValue, which will cause the model to
update 500 ms after the user finished typing over the input (that is, when the myValue finished updating).
Available object properties
1.
updateOn: specifies which event should be bound to the input
ng-model-options="{ updateOn: 'blur'}" // will update on blur
2.
debounce: specifies a delay of some millisecond towards the model update
ng-model-options="{'debounce': 500}" // will update the model after 1/2 second
3.
allowInvalid: a boolean flag allowing for an invalid value to the model, circumventing default form
validation, by default these values would be treated as undefined.
4.
getterSetter: a boolean flag indicating if to treat the ng-model as a getter/setter function instead of a plain
model value. The function will then run and return the model value.
Example:
<input type="text" ng-model="myFunc" ng-model-options="{'getterSetter': true}">
$scope.myFunc = function() {return "value";}
5.
timezone: defines the timezone for the model if the input is of the date or time. types
Section 4.8: ngCopy
The ngCopy directive specifies behavior to be run on a copy event.
Prevent a user from copying data
<p ng-copy="blockCopy($event)">This paragraph cannot be copied</p>
In the controller
$scope.blockCopy = function(event) {
 event.preventDefault();
 console.log("Copying won't work");
}
Section 4.9: ngPaste
The ngPaste directive specifies custom behavior to run when a user pastes content
<input ng-paste="paste=true" ng-init="paste=false" placeholder='paste here'>
pasted: {{paste}}
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Section 4.10: ngClick
The ng-click directive attaches a click event to a DOM element.
The ng-click directive allows you to specify custom behavior when an element of DOM is clicked.
It is useful when you want to attach click events on buttons and handle them at your controller.
This directive accepts an expression with the events object available as $event
HTML
<input ng-click="onClick($event)">Click me</input>
Controller
.controller("ctrl", function($scope) {
$scope.onClick = function(evt) {
 console.debug("Hello click event: %o ",evt);
 }
})
HTML
<button ng-click="count = count + 1" ng-init="count=0">
 Increment
</button>
<span>
 count: {{count}}
</span>
HTML
<button ng-click="count()" ng-init="count=0">
 Increment
</button>
<span>
 count: {{count}}
</span>
Controller
...
$scope.count = function(){
 $scope.count = $scope.count + 1;
}
...
When the button is clicked, an invocation of the onClick function will print "Hello click event" followed by the event
object.
Section 4.11: ngList
The ng-list directive is used to convert a delimited string from a text input to an array of strings or vice versa.
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The ng-list directive uses a default delimiter of ", " (comma space).
You can set the delimiter manually by assigning ng-list a delimeter like this ng-list="; ".
In this case the delimiter is set to a semi colon followed by a space.
By default ng-list has an attribute ng-trim which is set to true. ng-trim when false, will respect white space in
your delimiter. By default, ng-list does not take white space into account unless you set ng-trim="false".
Example:
angular.module('test', [])
 .controller('ngListExample', ['$scope', function($scope) {
 $scope.list = ['angular', 'is', 'cool!'];
}]);
A customer delimiter is set to be ;. And the model of the input box is set to the array that was created on the scope.
<body ng-app="test" ng-controller="ngListExample">
 <input ng-model="list" ng-list="; " ng-trim="false">
 </body>
The input box will display with the content: angular; is; cool!
Section 4.12: ngOptions
ngOptions is a directive that simplifies the creation of a html dropdown box for the selection of an item from an
array that will be stored in a model. The ngOptions attribute is used to dynamically generate a list of <option>
elements for the <select> element using the array or object obtained by evaluating the ngOptions comprehension
expression.
With ng-options the markup can be reduced to just a select tag and the directive will create the same select:
<select ng-model="selectedFruitNgOptions"
 ng-options="curFruit as curFruit.label for curFruit in fruit">
</select>
There is anther way of creating SELECT options using ng-repeat, but it is not recommended to use ng-repeat as it is
mostly used for general purpose like, the forEach just to loop. Whereas ng-options is specifically for creating
SELECT tag options.
Above example using ng-repeat would be
<select ng-model="selectedFruit">
 <option ng-repeat="curFruit in fruit" value="{{curFruit}}">
 {{curFruit.label}}
 </option>
</select>
FULL EXAMPLE
Lets see the above example in detail also with some variations in it.
Data model for the example:
$scope.fruit = [
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{ label: "Apples", value: 4, id: 2 },
 { label: "Oranges", value: 2, id: 1 },
 { label: "Limes", value: 4, id: 4 },
 { label: "Lemons", value: 5, id: 3 }
];
<!-- label for value in array -->
<select ng-options="f.label for f in fruit" ng-model="selectedFruit"></select>
Option tag generated on selection:
<option value="{ label: "Apples", value: 4, id: 2 }"> Apples </option>
Effects:
f.label will be the label of the <option> and the value will contain the entire object.
FULL EXAMPLE
<!-- select as label for value in array -->
<select ng-options="f.value as f.label for f in fruit" ng-model="selectedFruit"></select>
Option tag generated on selection:
<option value="4"> Apples </option>
Effects:
f.value (4) will be the value in this case while the label is still the same.
FULL EXAMPLE
<!-- label group by group for value in array -->
<select ng-options="f.label group by f.value for f in fruit" ng-model="selectedFruit"></select>
Option tag generated on selection:
<option value="{ label: "Apples", value: 4, id: 2 }"> Apples </option>
Effects:
Options will be grouped based on there value. Options with same value will fall under one category
FULL EXAMPLE
<!-- label disable when disable for value in array -->
<select ng-options="f.label disable when f.value == 4 for f in fruit" ng-
model="selectedFruit"></select>
Option tag generated on selection:
<option disabled="" value="{ label: "Apples", value: 4, id: 2 }"> Apples </option>
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Effects:
"Apples" and "Limes" will be disabled (unable to select) because of the condition disable when f.value==4. All
options with value=4 shall be disabled
FULL EXAMPLE
<!-- label group by group for value in array track by trackexpr -->
<select ng-options="f.value as f.label group by f.value for f in fruit track by f.id" ng-
model="selectedFruit"></select>
Option tag generated on selection:
<option value="4"> Apples </option>
Effects:
There is not visual change when using trackBy, but Angular will detect changes by the id instead of by reference
which is most always a better solution.
FULL EXAMPLE
<!-- label for value in array | orderBy:orderexpr track by trackexpr -->
<select ng-options="f.label for f in fruit | orderBy:'id' track by f.id" ng-
model="selectedFruit"></select>
Option tag generated on selection:
<option disabled="" value="{ label: "Apples", value: 4, id: 2 }"> Apples </option>
Effects:
orderBy is a AngularJS standard filter which arranges options in ascending order(by default) so "Oranges" in this will
appear 1st since its id = 1.
FULL EXAMPLE
All <select> with ng-options must have ng-model attached.
Section 4.13: ngSrc
Using Angular markup like {{hash}} in a src attribute doesn't work right. The browser will fetch from the URL with
the literal text {{hash}} until Angular replaces the expression inside {{hash}}. ng-src directive overrides the
original src attribute for the image tag element and solves the problem
<div ng-init="pic = 'pic_angular.jpg'">
 <h1>Angular</h1>
 <img ng-src="{{pic}}">
</div>
Section 4.14: ngModel
With ng-model you can bind a variable to any type of input field. You can display the variable using double curly
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braces, eg {{myAge}}.
<input type="text" ng-model="myName">
<p>{{myName}}</p>
As you type in the input field or change it in any way you will see the value in the paragraph update instantly.
The ng-model variable, in this instance, will be available in your controller as $scope.myName. If you are using the
controllerAs syntax:
<div ng-controller="myCtrl as mc">
 <input type="text" ng-model="mc.myName">
 <p>{{mc.myName}}</p>
</div>
You will need to refer to the controller's scope by pre-pending the controller's alias defined in the ng-controller
attribute to the ng-model variable. This way you won't need to inject $scope into your controller to reference your
ng-model variable, the variable will be available as this.myName inside your controller's function.
Section 4.15: ngClass
Let's assume that you need to show the status of a user and you have several possible CSS classes that could be
used. Angular makes it very easy to choose from a list of several possible classes which allow you to specify an
object list that include conditionals. Angular is able to use the correct class based on the truthiness of the
conditionals.
Your object should contain key/value pairs. The key is a class name that will be applied when the value (conditional)
evaluates to true.
<style>
 .active { background-color: green; color: white; }
 .inactive { background-color: gray; color: white; }
 .adminUser { font-weight: bold; color: yellow; }
 .regularUser { color: white; }
</style>
<span ng-class="{
 active: user.active,
 inactive: !user.active,
 adminUser: user.level === 1,
 regularUser: user.level === 2
}">John Smith</span>
Angular will check the $scope.user object to see the active status and the level number. Depending on the values
in those variables, Angular will apply the matching style to the <span>.
Section 4.16: ngDblclick
The ng-dblclick directive is useful when you want to bind a double-click event into your DOM elements.
This directive accepts an expression
HTML
<input type="number" ng-model="num = num + 1" ng-init="num=0">
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<button ng-dblclick="num++">Double click me</button>
In the above example, the value held at the input will be incremented when the button is double clicked.
Section 4.17: ngHref
ngHref is used instead of href attribute, if we have a angular expressions inside href value. The ngHref directive
overrides the original href attribute of an html tag using href attribute such as tag, tag etc.
The ngHref directive makes sure the link is not broken even if the user clicks the link before AngularJS has evaluated
the code.
Example 1
<div ng-init="linkValue = 'http://stackoverflow.com'">
 <p>Go to <a ng-href="{{linkValue}}">{{linkValue}}</a>!</p>
</div>
Example 2 This example dynamically gets the href value from input box and load it as href value.
<input ng-model="value" />
<a id="link" ng-href="{{value}}">link</a>
Example 3
<script>
angular.module('angularDoc', [])
.controller('myController', function($scope) {
 // Set some scope value.
 // Here we set bootstrap version.
 $scope.bootstrap_version = '3.3.7';
// Set the default layout value
 $scope.layout = 'normal';
});
</script>
<!-- Insert it into Angular Code -->
<link rel="stylesheet" ng-href="//maxcdn.bootstrapcdn.com/bootstrap/{{ bootstrap_version
}}/css/bootstrap.min.css">
<link rel="stylesheet" ng-href="layout-{{ layout }}.css">
Section 4.18: ngPattern
The ng-pattern directive accepts an expression that evaluates to a regular expression pattern and uses that
pattern to validate a textual input.
Example:
Lets say we want an <input> element to become valid when it's value (ng-model) is a valid IP address.
Template:
<input type="text" ng-model="ipAddr" ng-pattern="ipRegex" name="ip" required>
Controller:
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$scope.ipRegex =
/\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/;
Section 4.19: ngShow and ngHide
The ng-show directive shows or hides the HTML element based on if the expression passed to it is true or false. If
the value of the expression is falsy then it will hide. If it is truthy then it will show.
The ng-hide directive is similar. However, if the value is falsy it will show the HTML element. When the expression is
truthy it will hide it.
Working JSBin Example
Controller:
var app = angular.module('app', []);
angular.module('app')
 .controller('ExampleController', ExampleController);
function ExampleController() {
var vm = this;
//Binding the username to HTML element
 vm.username = '';
//A taken username
 vm.taken_username = 'StackOverflow';
}
View
<section ng-controller="ExampleController as main">
<p>Enter Password</p>
 <input ng-model="main.username" type="text">
<hr>
<!-- Will always show as long as StackOverflow is not typed in -->
 <!-- The expression is always true when it is not StackOverflow -->
 <div style="color:green;" ng-show="main.username != main.taken_username">
 Your username is free to use!
 </div>
<!-- Will only show when StackOverflow is typed in -->
 <!-- The expression value becomes falsy -->
 <div style="color:red;" ng-hide="main.username != main.taken_username">
 Your username is taken!
 </div>
<p>Enter 'StackOverflow' in username field to show ngHide directive.</p>
</section>
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Section 4.20: ngRequired
The ng-required adds or removes the required validation attribute on an element, which in turn will enable and
disable the require validation key for the input.
It is used to optionally define if an input element is required to have a non-empty value. The directive is helpful
when designing validation on complex HTML forms.
HTML
<input type="checkbox" ng-model="someBooleanValue">
<input type="text" ng-model="username" ng-required="someBooleanValue">
Section 4.21: ngMouseenter and ngMouseleave
The ng-mouseenter and ng-mouseleave directives are useful to run events and apply CSS styling when you hover
into or out of your DOM elements.
The ng-mouseenter directive runs an expression one a mouse enter event (when the user enters his mouse pointer
over the DOM element this directive resides in)
HTML
<div ng-mouseenter="applyStyle = true" ng-class="{'active': applyStyle}">
At the above example, when the user points his mouse over the div, applyStyle turns to true, which in turn
applies the .active CSS class at the ng-class.
The ng-mouseleave directive runs an expression one a mouse exit event (when the user takes his mouse cursor
away from the DOM element this directive resides in)
HTML
<div ng-mouseenter="applyStyle = true" ng-mouseleaver="applyStyle = false" ng-class="{'active':
applyStyle}">
Reusing the first example, now when the user takes him mouse pointer away from the div, the .active class is
removed.
Section 4.22: ngDisabled
This directive is useful to limit input events based on certain existing conditions.
The ng-disabled directive accepts and expression that should evaluate to either a truthy or a falsy values.
ng-disabled is used to conditionally apply the disabled attribute on an input element.
HTML
<input type="text" ng-model="vm.name">
<button ng-disabled="vm.name.length===0" ng-click="vm.submitMe">Submit</button>
vm.name.length===0 is evaluated to true if the input's length is 0, which is turn disables the button, disallowing the
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user to fire the click event of ng-click
Section 4.23: ngValue
Mostly used under ng-repeat ngValue is useful when dynamically generating lists of radio buttons using ngRepeat
<script>
 angular.module('valueExample', [])
 .controller('ExampleController', ['$scope', function($scope) {
 $scope.names = ['pizza', 'unicorns', 'robots'];
 $scope.my = { favorite: 'unicorns' };
 }]);
</script>
 <form ng-controller="ExampleController">
 <h2>Which is your favorite?</h2>
 <label ng-repeat="name in names" for="{{name}}">
 {{name}}
 <input type="radio"
 ng-model="my.favorite"
 ng-value="name"
 id="{{name}}"
 name="favorite">
 </label>
 <div>You chose {{my.favorite}}</div>
 </form>
Working plnkr
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Chapter 5: Use of in-built directives
Section 5.1: Hide/Show HTML Elements
This example hide show html elements.
<!DOCTYPE html>
<html ng-app="myDemoApp">
 <head>
 <script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
 <script>
function HideShowController() {
 var vm = this;
 vm.show=false;
 vm.toggle= function() {
 vm.show=!vm.show;
 }
 }
angular.module("myDemoApp", [/* module dependencies go here */])
 .controller("hideShowController", [HideShowController]);
 </script>
 </head>
 <body ng-cloak>
 <div ng-controller="hideShowController as vm">
 <a style="cursor: pointer;" ng-show="vm.show" ng-click="vm.toggle()">Show Me!</a>
 <a style="cursor: pointer;" ng-hide="vm.show" ng-click="vm.toggle()">Hide Me!</a>
 </div>
 </body>
</html>
Live Demo
Step by step explanation:
1.
ng-app="myDemoApp", the ngApp directive tells angular that a DOM element is controlled by a specific
angular.module named "myDemoApp".
<script src="[//angular include]"> include angular js.
HideShowController function is defined containing another function named toggle which help to hide show
the element.
angular.module(...) creates a new module.
.controller(...) Angular Controller and returns the module for chaining;
ng-controller directive is key aspect of how angular supports the principles behind the Model-View-
Controller design pattern.
ng-show directive shows the given HTML element if expression provided is true.
ng-hide directive hides the given HTML element if expression provided is true.
ng-click directive fires a toggle function inside controller
2.
3.
4.
5.
6.
7.
8.
9.
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Chapter 6: Custom Directives
Parameter
scope
Details
Property to set the scope of the directive. It can be set as false, true or as an isolate scope:
{ @, =, <, & }.
scope: falsy
Directive uses parent scope. No scope created for directive.
scope: true
scope: { @ }
scope: { = }
scope: { < }
Directive inherits parent scope prototypically as a new child scope. If there are multiple
directives on the same element requesting a new scope, then they will share one new
scope.
One way binding of a directive scope property to a DOM attribute value. As the attribute
value bound in the parent, it will change in the directive scope.
Bi-directional attribute binding that changes the attribute in the parent if the directive
attribute changes and vice-versa.
One way binding of a directive scope property and a DOM attribute expression. The
expression is evaluated in the parent. This watches the identity of the parent value so
changes to an object property in the parent won't be reflected in the directive. Changes to
an object property in a directive will be reflected in the parent, since both reference the
same object
scope: { & }
Allows the directive to pass data to an expression to be evaluated in the parent.
compile: function
link: function/object
pre-link function
post-link function
restrict: string
require:
'demoDirective'
require:
'?demoDirective'
require:
'^demoDirective'
require:
'^^demoDirective'
require:
'?^demoDirective'
This function is used to perform DOM transformation on the directive template before the
link function runs. It accepts tElement ( the directive template ) and tAttr ( list of
attributes declared on the directive ). It does not have access to the scope. It may return a
function that will be registered as a post-link function or it may return an object with pre
and post properties with will be registered as the pre-link and post-link functions.
The link property can be configured as a function or object. It can receive the following
arguments: scope(directive scope), iElement( DOM element where directive is applied ),
iAttrs( collection of DOM element attributes ), controller( array of controllers required by
directive ), transcludeFn. It is mainly used to for setting up DOM listeners, watching model
properties for changes, and updating the DOM. It executes after the template is cloned. It
is configured independently if there is no compile function.
Link function that executes before any child link functions. By default, child directive link
functions execute before parent directive link functions and the pre-link function enables
the parent to link first. One use case is if the child requires data from the parent.
Link function that executives after child elements are linked to parent. It is commonly used
for attaching event handlers and accessing child directives, but data required by the child
directive should not be set here because the child directive will have already been linked.
Defines how to call the directive from within the DOM. Possible values (Assuming our
directive name is demoDirective): E - Element name (<demo-directive></demo-
directive>), A - Attribute (<div demo-directive></div>), C - Matching class (<div
class="demo-directive"></div>), M - By comment (<!-- directive: demo-directive -
->). The restrict property can also support multiple options, for example - restrict:
"AC" will restrict the directive to Attribute OR Class. If omitted, the default value is "EA"
(Element or Attribute).
Locate demoDirective's controller on the current element and inject its controller as the
fourth argument to the linking function. Throw an error if not found.
Attempt to locate the demoDirective's controller or pass null to the link fn if not found.
Locate the demoDirective's controller by searching the element and its parents. Throw an
error if not found.
Locate the demoDirective's controller by searching the element's parents. Throw an error
if not found.
Attempt to locate the demoDirective's controller by searching the element and its parents
or pass null to the link fn if not found.
require:
'?^^demoDirective'
Attempt to locate the demoDirective's controller by searching the element's parents, or
pass null to the link fn if not found.
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Here you will learn about the Directives feature of AngularJS. Below you will find information on what Directives are,
as well as Basic and Advanced examples of how to use them.
Section 6.1: Creating and consuming custom directives
Directives are one of the most powerful features of angularjs. Custom angularjs directives are used to extend
functionality of html by creating new html elements or custom attributes to provide certain behavior to an html tag.
directive.js
// Create the App module if you haven't created it yet
var demoApp= angular.module("demoApp", []);
// If you already have the app module created, comment the above line and create a reference of the
app module
var demoApp = angular.module("demoApp");
// Create a directive using the below syntax
// Directives are used to extend the capabilities of html element
// You can either create it as an Element/Attribute/class
// We are creating a directive named demoDirective. Notice it is in CamelCase when we are defining
the directive just like ngModel
// This directive will be activated as soon as any this element is encountered in html
demoApp.directive('demoDirective', function () {
// This returns a directive definition object
 // A directive definition object is a simple JavaScript object used for configuring the directive’s
behaviour,template..etc
 return {
 // restrict: 'AE', signifies that directive is Element/Attribute directive,
 // "E" is for element, "A" is for attribute, "C" is for class, and "M" is for comment.
 // Attributes are going to be the main ones as far as adding behaviors that get used the most.
 // If you don't specify the restrict property it will default to "A"
 restrict :'AE',
// The values of scope property decides how the actual scope is created and used inside a
directive. These values can be either “false”, “true” or “{}”. This creates an isolate scope for the
directive.
 // '@' binding is for passing strings. These strings support {{}} expressions for interpolated
values.
 // '=' binding is for two-way model binding. The model in parent scope is linked to the model in
the directive's isolated scope.
 // '&' binding is for passing a method into your directive's scope so that it can be called
within your directive.
 // The method is pre-bound to the directive's parent scope, and supports arguments.
 scope: {
 name: "@", // Always use small casing here even if it's a mix of 2-3 words
 },
// template replaces the complete element with its text.
 template: "<div>Hello {{name}}!</div>",
// compile is called during application initialization. AngularJS calls it once when html page is
loaded.
 compile: function(element, attributes) {
 element.css("border", "1px solid #cccccc");
// linkFunction is linked with each element with scope to get the element specific data.
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var linkFunction = function($scope, element, attributes) {
 element.html("Name: <b>"+$scope.name +"</b>");
 element.css("background-color", "#ff00ff");
 };
 return linkFunction;
 }
 };
});
This directive can then be used in App as :
<html>
<head>
 <title>Angular JS Directives</title>
 </head>
 <body>
 <script src = "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
 <script src="directive.js"></script>
<div ng-app = "demoApp">
 <!-- Notice we are using Spinal Casing here -->
<demo-directive name="World"></demo-directive>
</div>
 </body>
</html>
Section 6.2: Directive Definition Object Template
demoApp.directive('demoDirective', function () {
 var directiveDefinitionObject = {
 multiElement:
priority:
 terminal:
 scope: {},
bindToController: {},
 controller:
 controllerAs:
 require:
 restrict:
 templateNamespace:
 template:
 templateUrl:
 transclude:
 compile:
 link: function(){}
};
 return directiveDefinitionObject;
});
1.
multiElement - set to true and any DOM nodes between the start and end of the directive name will be
collected and grouped together as directive elements
2.
priority - allows specification of the order to apply directives when multiple directives are defined on a
single DOM element. Directives with higher numbers are compiled first.
terminal - set to true and the current priority will be the last set of directives to execute
scope - sets scope of the directive
bind to controller - binds scope properties directly to directive controller
controller - controller constructor function
3.
4.
5.
6.
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7.
8.
require - require another directive and inject its controller as the fourth argument to the linking function
controllerAs - name reference to the controller in the directive scope to allow the controller to be
referenced from the directive template.
9.
restrict - restrict directive to Element, Attribute, Class, or Comment
10.
templateNameSpace - sets document type used by directive template: html, svg, or math. html is the default
11.
template - html markup that defaults to replacing the content of the directive's element, or wraps the
contents of the directive element if transclude is true
12.
templateUrl - url provided asynchronously for the template
13.
transclude - Extract the contents of the element where the directive appears and make it available to the
directive. The contents are compiled and provided to the directive as a transclusion function.
14.
compile - function to transform the template DOM
15.
link - only used if the compile property is not defined. The link function is responsible for registering DOM
listeners as well as updating the DOM. It is executed after the template has been cloned.
Section 6.3: How to create resuable component using
directive
AngularJS directives are what controls the rendering of the HTML inside an AngularJS application. They can be an
Html element, attribute, class or a comment. Directives are used to manipulate the DOM, attaching new behavior to
HTML elements, data binding and many more. Some of examples of directives which angular provides are ng-
model, ng-hide, ng-if.
Similarly one can create his own custom directive and make them resuable. For creating Custom directives
Reference. The sense behind creating reusable directives is to make a set of directives/components written by you
just like angularjs provides us using angular.js . These reusable directives can be particularly very helpful when you
have suite of applications/application which requires a consistent behavior, look and feel. An example of such
reusable component can be a simple toolbar which you may want to use across your application or different
applications but you want them to behave the same or look the same.
Firstly , Make a folder named resuableComponents in your app Folder and make reusableModuleApp.js
reusableModuleApp.js:
(function(){
var reusableModuleApp = angular.module('resuableModuleApp', ['ngSanitize']);
//Remember whatever dependencies you have in here should be injected in the app module where it is
intended to be used or it's scripts should be included in your main app
//We will be injecting ng-sanitize
resubaleModuleApp.directive('toolbar', toolbar)
toolbar.$inject=['$sce'];
function toolbar($sce){
return{
 restrict :'AE',
 //Defining below isolate scope actually provides window for the directive to take data from
app that will be using this.
 scope : {
 value1: '=',
 value2: '=',
 },
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}
 template : '<ul> <li><a ng-click="Add()" href="">{{value1}}</a></li> <li><a ng-
click="Edit()" href="#">{{value2}}</a></li> </ul> ',
 link : function(scope, element, attrs){
//Handle's Add function
 scope.Add = function(){
};
//Handle's Edit function
 scope.Edit = function(){
};
 }
 }
});
mainApp.js:
(function(){
 var mainApp = angular.module('mainApp', ['reusableModuleApp']); //Inject resuableModuleApp in
your application where you want to use toolbar component
mainApp.controller('mainAppController', function($scope){
 $scope.value1 = "Add";
 $scope.value2 = "Edit";
});
});
index.html:
<!doctype html>
 <html ng-app="mainApp">
 <head>
 <title> Demo Making a reusable component
 <head>
 <body ng-controller="mainAppController">
<!-- We are providing data to toolbar directive using mainApp'controller -->
 <toolbar value1="value1" value2="value2"></toolbar>
<!-- We need to add the dependent js files on both apps here -->
 <script src="js/angular.js"></script>
 <script src="js/angular-sanitize.js"></script>
<!-- your mainApp.js should be added afterwards --->
 <script src="mainApp.js"></script>
<!-- Add your reusable component js files here -->
 <script src="resuableComponents/reusableModuleApp.js"></script>
</body>
 </html>
Directive are reusable components by default. When you make directives in separate angular module, It actually
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makes it exportable and reusable across different angularJs applications. New directives can simply be added inside
reusableModuleApp.js and reusableModuleApp can have it's own controller, services, DDO object inside directive to
define the behavior.
Section 6.4: Basic Directive example
superman-directive.js
angular.module('myApp', [])
 .directive('superman', function() {
 return {
 // restricts how the directive can be used
 restrict: 'E',
 templateUrl: 'superman-template.html',
 controller: function() {
 this.message = "I'm superman!"
 },
 controllerAs: 'supermanCtrl',
 // Executed after Angular's initialization. Use commonly
 // for adding event handlers and DOM manipulation
 link: function(scope, element, attributes) {
 element.on('click', function() {
 alert('I am superman!')
 });
 }
 }
 });
superman-template.html
<h2>{{supermanCtrl.message}}</h2>
index.html
<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>Document</title>
 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.0/angular.js"></script>
 <script src="superman-directive.js"><script/>
</head>
<body>
<div ng-app="myApp">
 <superman></superman>
</div>
</body>
</html>
You can check out more about directive's restrict and link functions on AngularJS's official documentation on
Directives
Section 6.5: Directive decorator
Sometimes you may need additional features from a directive. Instead of rewriting (copy) the directive, you can
modify how the directive behaves.
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The decorator will be executed during $inject phase.
To do so, provde a .config to your module. The directive is called myDirective, so you have to config
myDirectiveDirective. (this in an angular convention [read about providers] ).
This example will change the templateUrl of the directive:
angular.module('myApp').config(function($provide){
 $provide.decorator('myDirectiveDirective', function($delegate){
 var directive = $delegate[0]; // this is the actual delegated, your directive
 directive.templateUrl = 'newTemplate.html'; // you change the directive template
 return $delegate;
 })
});
This example add an onClick event to the directive element when clicked, this happens during compile phase.
angular.module('myApp').config(function ($provide) {
 $provide.decorator('myDirectiveTwoDirective', function ($delegate) {
 var directive = $delegate[0];
 var link = directive.link; // this is directive link phase
 directive.compile = function () { // change the compile of that directive
 return function (scope, element, attrs) {
 link.apply(this, arguments); // apply this at the link phase
 element.on('click', function(){ // when add an onclick that log hello when the
directive is clicked.
 console.log('hello!');
 });
 };
 };
 return $delegate;
 });
});
Similar approach can be used for both Providers and Services.
Section 6.6: Basic directive with template and an isolated
scope
Creating a custom directive with isolated scope will separate the scope inside the directive from the outside scope,
in order to prevent our directive from accidentally change the data in the parent scope and restricting it from
reading private data from the parent scope.
To create an isolated scope and still allow our custom directive to communicate with the outside scope, we can use
the scope option that describe how to map the bindings of the directive's inner scope with the outside scope.
The actual bindings are made with extra attributes attached to the directive. The binding settings are defined with
the scope option and an object with key-value pairs:
A key, which is corresponded to our directive's isolated scope property
A value, which tells Angular how do bind the directive inner scope to a matching attribute
Simple example of a directive with an isolated scope:
var ProgressBar = function() {
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return {
 scope: { // This is how we define an isolated scope
 current: '=', // Create a REQUIRED bidirectional binding by using the 'current' attribute
 full: '=?maxValue' // Create an OPTIONAL (Note the '?'): bidirectional binding using 'max-
value' attribute to the `full` property in our directive isolated scope
 }
 template: '<div class="progress-back">' +
 ' <div class="progress-bar"' +
 ' ng-style="{width: getProgress()}">' +
 ' </div>' +
 '</div>',
 link: function(scope, el, attrs) {
 if (scope.full === undefined) {
 scope.full = 100;
 }
 scope.getProgress = function() {
 return (scope.current / scope.size * 100) + '%';
 }
 }
 }
}
ProgressBar.$inject = [];
angular.module('app').directive('progressBar', ProgressBar);
Example how to use this directive and bind data from the controller's scope to the directive's inner scope:
Controller:
angular.module('app').controller('myCtrl', function($scope) {
 $scope.currentProgressValue = 39;
 $scope.maxProgressBarValue = 50;
});
View:
<div ng-controller="myCtrl">
 <progress-bar current="currentProgressValue"></progress-bar>
 <progress-bar current="currentProgressValue" max-value="maxProgressBarValue"></progress-bar>
</div>
Section 6.7: Building a reusable component
Directives can be used to build reusable components. Here is an example of a "user box" component:
userBox.js
angular.module('simpleDirective', []).directive('userBox', function() {
 return {
 scope: {
 username: '=username',
 reputation: '=reputation'
 },
 templateUrl: '/path/to/app/directives/user-box.html'
 };
});
Controller.js
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var myApp = angular.module('myApp', ['simpleDirective']);
myApp.controller('Controller', function($scope) {
$scope.user = "John Doe";
 $scope.rep = 1250;
$scope.user2 = "Andrew";
 $scope.rep2 = 2850;
});
myPage.js
<html lang="en" ng-app="myApp">
 <head>
 <script src="/path/to/app/angular.min.js"></script>
 <script src="/path/to/app/js/controllers/Controller.js"></script>
 <script src="/path/to/app/js/directives/userBox.js"></script>
 </head>
<body>
<div ng-controller="Controller">
 <user-box username="user" reputation="rep"></user-box>
 <user-box username="user2" reputation="rep2"></user-box>
 </div>
</body>
</html>
user-box.html
<div>{{username}}</div>
<div>{{reputation}} reputation</div>
The result will be:
John Doe
1250 reputation
Andrew
2850 reputation
Section 6.8: Directive inheritance and interoperability
Angular js directives can be nested or be made interoperable.
In this example, directive Adir exposes to directive Bdir it's controller $scope, since Bdir requires Adir.
angular.module('myApp',[]).directive('Adir', function () {
 return {
 restrict: 'AE',
 controller: ['$scope', function ($scope) {
 $scope.logFn = function (val) {
 console.log(val);
 }
 }]
 }
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})
Make sure to set require: '^Adir' (look at the angular documentation, some versions doesn't require ^ character).
.directive('Bdir', function () {
 return {
 restrict: 'AE',
 require: '^Adir', // Bdir require Adir
 link: function (scope, elem, attr, Parent) {
 // Parent is Adir but can be an array of required directives.
 elem.on('click', function ($event) {
 Parent.logFn("Hello!"); // will log "Hello! at parent dir scope
 scope.$apply(); // apply to parent scope.
 });
 }
 }
 }]);
You can nest your directive in this way:
<div a-dir><span b-dir></span></div>
<a-dir><b-dir></b-dir> </a-dir>
Is not required that directives are nested in your HTML.
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Chapter 7: How data binding works
Section 7.1: Data Binding Example
<p ng-bind="message"></p>
This 'message' has to be attached to the current elements controller's scope.
$scope.message = "Hello World";
At a later point of time , even if the message model is updated , that updated value is reflected in the HTML
element. When angular compiles the template "Hello World" will be attached to the innerHTML of the current
world. Angular maintains a Watching mechanism of all the directives atttached to the view. It has a Digest Cycle
mechanism where it iterates through the Watchers array, it will update the DOM element if there is a change in the
previous value of the model.
There is no periodic checking of Scope whether there is any change in the Objects attached to it. Not all the objects
attached to scope are watched . Scope prototypically maintains a $$WatchersArray . Scope only iterates through
this WatchersArray when $digest is called .
Angular adds a watcher to the WatchersArray for each of these
1.
{{expression}} — In your templates (and anywhere else where there’s an expression) or when we
define ng-model.
2.
$scope.$watch(‘expression/function’) — In your JavaScript we can just attach a scope object for
angular to watch.
$watch function takes in three parameters:
1.
First one is a watcher function which just returns the object or we can just add an expression.
2.
Second one is a listener function which will be called when there is a change in the object. All the
things like DOM changes will be implemented in this function.
3.
The third being an optional parameter which takes in a boolean . If its true , angular deep watches
the object & if its false Angular just does a reference watching on the object. Rough
Implementation of $watch looks like this
Scope.prototype.$watch = function(watchFn, listenerFn) {
 var watcher = {
 watchFn: watchFn,
 listenerFn: listenerFn || function() { },
 last: initWatchVal // initWatchVal is typically undefined
 };
 this.$$watchers.push(watcher); // pushing the Watcher Object to Watchers
};
There is an interesting thing in Angular called Digest Cycle. The $digest cycle starts as a result of a call to
$scope.$digest(). Assume that you change a $scope model in a handler function through the ng-click directive. In
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that case AngularJS automatically triggers a $digest cycle by calling $digest().In addition to ng-click, there are several
other built-in directives/services that let you change models (e.g. ng-model, $timeout, etc) and automatically trigger
a $digest cycle. The rough implementation of $digest looks like this.
Scope.prototype.$digest = function() {
 var dirty;
 do {
 dirty = this.$$digestOnce();
 } while (dirty);
}
Scope.prototype.$$digestOnce = function() {
 var self = this;
 var newValue, oldValue, dirty;
 _.forEach(this.$$watchers, function(watcher) {
 newValue = watcher.watchFn(self);
 oldValue = watcher.last; // It just remembers the last value for dirty checking
 if (newValue !== oldValue) { //Dirty checking of References
 // For Deep checking the object , code of Value
// based checking of Object should be implemented here
 watcher.last = newValue;
 watcher.listenerFn(newValue,
 (oldValue === initWatchVal ? newValue : oldValue),
 self);
 dirty = true;
 }
 });
 return dirty;
 };
If we use JavaScript’s setTimeout() function to update a scope model, Angular has no way of knowing what you
might change. In this case it’s our responsibility to call $apply() manually, which triggers a $digest cycle. Similarly, if
you have a directive that sets up a DOM event listener and changes some models inside the handler function, you
need to call $apply() to ensure the changes take effect. The big idea of $apply is that we can execute some code that
isn't aware of Angular, that code may still change things on the scope. If we wrap that code in $apply , it will take
care of calling $digest(). Rough implementation of $apply().
Scope.prototype.$apply = function(expr) {
 try {
 return this.$eval(expr); //Evaluating code in the context of Scope
 } finally {
 this.$digest();
 }
};
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Chapter 8: Angular Project - Directory
Structure
Section 8.1: Directory Structure
A common question among new Angular programmers - "What should be the structure of the project?". A good
structure helps toward a scalable application development. When we start a project we have two choices, Sort By
Type (left) and Sort By Feature (right). The second is better, especially in large applications, the project becomes a
lot easier to manage.
Sort By Type (left)
The application is organized by the files' type.
Advantage - Good for small apps, for programmers only starting to use Angular, and is easy to convert to
the second method.
Disadvantage - Even for small apps it starts to get more difficult to find a specific file. For instance, a view
and it's controller are in two separate folders.
Sort By Feature (right)
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The suggested organizing method where the filed are sorted by features' type.
All of the layout views and controllers go in the layout folder, the admin content goes in the admin folder, and so
on.
Advantage - When looking for a section of code determining a certain feature it's all located in one folder.
Disadvantage - Services are a bit different as they “service” many features.
You can read more about it on Angular Structure: Refactoring for Growth
The suggested file structure combining both of the aforementioned methods:
Credit to: Angular Style Guide
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Chapter 9: Filters
Section 9.1: Accessing a filtered list from outside an ng-repeat
Occasionally you will want to access the result of your filters from outside the ng-repeat, perhaps to indicate the
number of items that have been filtered out. You can do this using as [variablename] syntax on the ng-repeat.
<ul>
 <li ng-repeat="item in vm.listItems | filter:vm.myFilter as filtered">
 {{item.name}}
 </li>
</ul>
<span>Showing {{filtered.length}} of {{vm.listItems.length}}</span>
Section 9.2: Custom filter to remove values
A typical use case for a filter is to remove values from an array. In this example we pass in an array and remove any
nulls found in it, returning the array.
function removeNulls() {
 return function(list) {
 for (var i = list.length - 1; i >= 0; i--) {
 if (typeof list[i] === 'undefined' ||
 list[i] === null) {
 list.splice(i, 1);
 }
 }
 return list;
 };
}
That would be used in the HTML like
{{listOfItems | removeNulls}}
or in a controller like
listOfItems = removeNullsFilter(listOfItems);
Section 9.3: Custom filter to format values
Another use case for filters is to format a single value. In this example, we pass in a value and we are returned an
appropriate true boolean value.
function convertToBooleanValue() {
 return function(input) {
 if (typeof input !== 'undefined' &&
 input !== null &&
 (input === true || input === 1 || input === '1' || input
 .toString().toLowerCase() === 'true')) {
 return true;
 }
 return false;
 };
}
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Which in the HTML would be used like this:
{{isAvailable | convertToBooleanValue}}
Or in a controller like:
var available = convertToBooleanValueFilter(isAvailable);
Section 9.4: Using filters in a controller or service
By injecting $filter, any defined filter in your Angular module may be used in controllers, services, directives or
even other filters.
angular.module("app")
 .service("users", usersService)
 .controller("UsersController", UsersController);
function usersService () {
 this.getAll = function () {
 return [{
 id: 1,
 username: "john"
 }, {
 id: 2,
 username: "will"
 }, {
 id: 3,
 username: "jack"
 }];
 };
}
function UsersController ($filter, users) {
 var orderByFilter = $filter("orderBy");
this.users = orderByFilter(users.getAll(), "username");
 // Now the users are ordered by their usernames: jack, john, will
this.users = orderByFilter(users.getAll(), "username", true);
 // Now the users are ordered by their usernames, in reverse order: will, john, jack
}
Section 9.5: Performing filter in a child array
This example was done in order to demonstrate how you can perform a deep filter in a child array without the
necessity of a custom filter.
Controller:
(function() {
 "use strict";
 angular
 .module('app', [])
 .controller('mainCtrl', mainCtrl);
function mainCtrl() {
 var vm = this;
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vm.classifications = ["Saloons", "Sedans", "Commercial vehicle", "Sport car"];
 vm.cars = [
{
"name":"car1",
 "classifications":[
{
"name":"Saloons"
 },
 {
"name":"Sedans"
 }
 ]
 },
 {
"name":"car2",
 "classifications":[
{
"name":"Saloons"
 },
 {
"name":"Commercial vehicle"
 }
 ]
 },
 {
"name":"car3",
 "classifications":[
{
"name":"Sport car"
 },
 {
"name":"Sedans"
 }
 ]
 }
 ];
 }
})();
View:
<body ng-app="app" ng-controller="mainCtrl as main">
 Filter car by classification:
 <select ng-model="classificationName"
 ng-options="classification for classification in main.classifications"></select>
 <br>
 <ul>
 <li ng-repeat="car in main.cars |
 filter: { classifications: { name: classificationName } } track by $index"
 ng-bind-template="{{car.name}} - {{car.classifications | json}}">
 </li>
 </ul>
</body>
Check the complete DEMO .
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Chapter 10: Custom filters
Section 10.1: Use a filter in a controller, a service or a filter
You will have to inject $filter:
angular
 .module('filters', [])
 .filter('percentage', function($filter) {
 return function (input) {
 return $filter('number')(input * 100) + ' %';
 };
 });
Section 10.2: Create a filter with parameters
By default, a filter has a single parameter: the variable it is applied on. But you can pass more parameter to the
function:
angular
 .module('app', [])
 .controller('MyController', function($scope) {
 $scope.example = 0.098152;
 })
 .filter('percentage', function($filter) {
 return function (input, decimals) {
 return $filter('number')(input * 100, decimals) + ' %';
 };
 });
Now, you can give a precision to the percentage filter:
<span ng-controller="MyController">{{ example | percentage: 2 }}</span>
=> "9.81 %"
... but other parameters are optional, you can still use the default filter:
<span ng-controller="MyController">{{ example | percentage }}</span>
=> "9.8152 %"
Section 10.3: Simple filter example
Filters format the value of an expression for display to the user. They can be used in view templates, controllers or
services. This example creates a filter (addZ) then uses it in a view. All this filter does is add a capital 'Z' to the end of
the string.
example.js
angular.module('main', [])
 .filter('addZ', function() {
 return function(value) {
 return value + "Z";
 }
 })
 .controller('MyController', ['$scope', function($scope) {
 $scope.sample = "hello";
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}])
example.html
Inside the view, the filter is applied with the following syntax: { variable | filter}. In this case, the variable we
defined in the controller, sample, is being filtered by the filter we created, addZ.
<div ng-controller="MyController">
 <span>{{sample | addZ}}</span>
</div>
Expected output
helloZ
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Chapter 11: Constants
Section 11.1: Create your first constant
angular
 .module('MyApp', [])
 .constant('VERSION', 1.0);
Your constant is now declared and can be injected in a controller, a service, a factory, a provider, and even in a
config method:
angular
 .module('MyApp')
 .controller('FooterController', function(VERSION) {
 this.version = VERSION;
 });
<footer ng-controller="FooterController as Footer">{{ Footer.version }}</footer>
Section 11.2: Use cases
There is no revolution here, but angular constant can be useful specially when your application and/or team starts
to grow ... or if you simply love writing beautiful code!
Refactor code. Example with event's names. If you use a lot of events in your application, you have event's
names a little every where. A when a new developer join your team, he names his events with a different
syntax, ... You can easily prevent this by grouping your event's names in a constant:
angular
 .module('MyApp')
 .constant('EVENTS', {
 LOGIN_VALIDATE_FORM: 'login::click-validate',
 LOGIN_FORGOT_PASSWORD: 'login::click-forgot',
 LOGIN_ERROR: 'login::notify-error',
 ...
 });
angular
 .module('MyApp')
 .controller('LoginController', function($scope, EVENT) {
 $scope.$on(EVENT.LOGIN_VALIDATE_FORM, function() {
 ...
 });
 })
... and now, your event's names can take benefits from autocompletion !
Define configuration. Locate all your configuration in a same place:
angular
 .module('MyApp')
 .constant('CONFIG', {
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BASE_URL: {
 APP: 'http://localhost:3000',
 API: 'http://localhost:3001'
 },
 STORAGE: 'S3',
 ...
 });
Isolate parts. Sometimes, there are some things you are not very proud of ... like hardcoded value for
example. Instead of let them in your main code, you can create an angular constant
angular
 .module('MyApp')
 .constant('HARDCODED', {
 KEY: 'KEY',
 RELATION: 'has_many',
 VAT: 19.6
 });
... and refactor something like
$scope.settings = {
 username: Profile.username,
 relation: 'has_many',
 vat: 19.6
}
to
$scope.settings = {
 username: Profile.username,
 relation: HARDCODED.RELATION,
 vat: HARDCODED.VAT
}
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Chapter 12: Custom filters with ES6
Section 12.1: FileSize Filter using ES6
We have here a file Size filter to describe how to add costum filter to an existing module :
let fileSize=function (size,unit,fixedDigit) {
return size.toFixed(fixedDigit) + ' '+unit;
};
let fileSizeFilter=function () {
 return function (size) {
 if (isNaN(size))
 size = 0;
if (size < 1024)
 return size + ' octets';
size /= 1024;
if (size < 1024)
 return fileSize(size,'Ko',2);
size /= 1024;
if (size < 1024)
 return fileSize(size,'Mo',2);
size /= 1024;
if (size < 1024)
 return fileSize(size,'Go',2);
size /= 1024;
 return fileSize(size,'To',2);
 };
 };
export default fileSizeFilter;
The filter call into the module :
import fileSizeFilter from 'path...';
let myMainModule =
 angular.module('mainApp', [])
 .filter('fileSize', fileSizeFilter);
The html code where we call the filter :
<div ng-app="mainApp">
<div>
<input type="text" ng-model="size" />
 </div>
 <div>
 <h3>Output:</h3>
 <p>{{size| Filesize}}</p>
 </div>
</div>
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Chapter 13: Directives using
ngModelController
Section 13.1: A simple control: rating
Let us build a simple control, a rating widget, intended to be used as:
<rating min="0" max="5" nullifier="true" ng-model="data.rating"></rating>
No fancy CSS for now; this would render as:
0 1 2 3 4 5 x
Clicking on a number selects that rating; and clicking the "x" sets the rating to null.
app.directive('rating', function() {
function RatingController() {
 this._ngModel = null;
 this.rating = null;
 this.options = null;
 this.min = typeof this.min === 'number' ? this.min : 1;
 this.max = typeof this.max === 'number' ? this.max : 5;
 }
RatingController.prototype.setNgModel = function(ngModel) {
 this._ngModel = ngModel;
if( ngModel ) {
 // KEY POINT 1
 ngModel.$render = this._render.bind(this);
 }
 };
RatingController.prototype._render = function() {
 this.rating = this._ngModel.$viewValue != null ? this._ngModel.$viewValue : -
Number.MAX_VALUE;
 };
RatingController.prototype._calculateOptions = function() {
 if( this.min == null || this.max == null ) {
 this.options = [];
 }
 else {
 this.options = new Array(this.max - this.min + 1);
 for( var i=0; i < this.options.length; i++ ) {
 this.options[i] = this.min + i;
 }
 }
 };
RatingController.prototype.setValue = function(val) {
 this.rating = val;
 // KEY POINT 2
 this._ngModel.$setViewValue(val);
 };
// KEY POINT 3
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Object.defineProperty(RatingController.prototype, 'min', {
 get: function() {
 return this._min;
 },
 set: function(val) {
 this._min = val;
 this._calculateOptions();
 }
 });
Object.defineProperty(RatingController.prototype, 'max', {
 get: function() {
 return this._max;
 },
 set: function(val) {
 this._max = val;
 this._calculateOptions();
 }
 });
return {
 restrict: 'E',
 scope: {
 // KEY POINT 3
 min: '<?',
 max: '<?',
 nullifier: '<?'
 },
 bindToController: true,
 controllerAs: 'ctrl',
 controller: RatingController,
 require: ['rating', 'ngModel'],
 link: function(scope, elem, attrs, ctrls) {
 ctrls[0].setNgModel(ctrls[1]);
 },
 template:
 '<span ng-repeat="o in ctrl.options" href="#" class="rating-option" ng-
class="{\'rating-option-active\': o <= ctrl.rating}" ng-click="ctrl.setValue(o)">{{ o }}</span>' +
 '<span ng-if="ctrl.nullifier" ng-click="ctrl.setValue(null)" class="rating-
nullifier">&#10006;</span>'
 };
});
Key points:
1.
2.
3.
Implement ngModel.$render to transfer the model's view value to your view.
Call ngModel.$setViewValue() whenever you feel the view value should be updated.
The control can of course be parameterized; use '<' scope bindings for parameters, if in Angular >= 1.5 to
clearly indicate input - one way binding. If you have to take action whenever a parameter changes, you can
use a JavaScript property (see Object.defineProperty()) to save a few watches.
Note 1: In order not to overcomplicate the implementation, the rating values are inserted in an array - the
ctrl.options. This is not needed; a more efficient, but also more complex, implementation could use DOM
manipulation to insert/remove ratings when min/max change.
Note 2: With the exception of the '<' scope bindings, this example can be used in Angular < 1.5. If you are on
Angular >= 1.5, it would be a good idea to transform this to a component and use the $onInit() lifecycle hook to
initialize min and max, instead of doing so in the controller's constructor.
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And a necessary fiddle: https://jsfiddle.net/h81mgxma/
Section 13.2: A couple of complex controls: edit a full object
A custom control does not have to limit itself to trivial things like primitives; it can edit more interesting things. Here
we present two types of custom controls, one for editing persons and one for editing addresses. The address
control is used to edit the person's address. An example of usage would be:
<input-person ng-model="data.thePerson"></input-person>
<input-address ng-model="data.thePerson.address"></input-address>
The model for this example is deliberately simplistic:
function Person(data) {
 data = data || {};
 this.name = data.name;
 this.address = data.address ? new Address(data.address) : null;
}
function Address(data) {
 data = data || {};
 this.street = data.street;
 this.number = data.number;
}
The address editor:
app.directive('inputAddress', function() {
InputAddressController.$inject = ['$scope'];
 function InputAddressController($scope) {
 this.$scope = $scope;
 this._ngModel = null;
 this.value = null;
 this._unwatch = angular.noop;
 }
InputAddressController.prototype.setNgModel = function(ngModel) {
 this._ngModel = ngModel;
if( ngModel ) {
 // KEY POINT 3
 ngModel.$render = this._render.bind(this);
 }
 };
InputAddressController.prototype._makeWatch = function() {
 // KEY POINT 1
 this._unwatch = this.$scope.$watchCollection(
 (function() {
 return this.value;
 }).bind(this),
 (function(newval, oldval) {
 if( newval !== oldval ) { // skip the initial trigger
 this._ngModel.$setViewValue(newval !== null ? new Address(newval) : null);
 }
 }).bind(this)
 );
 };
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InputAddressController.prototype._render = function() {
 // KEY POINT 2
 this._unwatch();
 this.value = this._ngModel.$viewValue ? new Address(this._ngModel.$viewValue) : null;
 this._makeWatch();
 };
return {
 restrict: 'E',
 scope: {},
 bindToController: true,
 controllerAs: 'ctrl',
 controller: InputAddressController,
 require: ['inputAddress', 'ngModel'],
 link: function(scope, elem, attrs, ctrls) {
 ctrls[0].setNgModel(ctrls[1]);
 },
 template:
 '<div>' +
 '<label><span>Street:</span><input type="text" ng-model="ctrl.value.street"
/></label>' +
 '<label><span>Number:</span><input type="text" ng-model="ctrl.value.number"
/></label>' +
 '</div>'
 };
});
Key points:
1.
We are editing an object; we do not want to change directly the object given to us from our parent (we want
our model to be compatible with the immutability principle). So we create a shallow watch on the object
being edited and update the model with $setViewValue() whenever a property changes. We pass a copy to
our parent.
2.
Whenever the model changes from the outside, we copy it and save the copy to our scope. Immutability
principles again, though the internal copy is not immutable, the external could very well be. Additionally we
rebuild the watch (this_unwatch();this._makeWatch();), to avoid triggering the watcher for changes
pushed to us by the model. (We only want the watch to trigger for changes made in the UI.)
3.
Other that the points above, we implement ngModel.$render() and call ngModel.$setViewValue() as we
would for a simple control (see the rating example).
The code for the person custom control is almost identical. The template is using the <input-address>. In a more
advanced implementation we could extract the controllers in a reusable module.
app.directive('inputPerson', function() {
InputPersonController.$inject = ['$scope'];
 function InputPersonController($scope) {
 this.$scope = $scope;
 this._ngModel = null;
 this.value = null;
 this._unwatch = angular.noop;
 }
InputPersonController.prototype.setNgModel = function(ngModel) {
 this._ngModel = ngModel;
if( ngModel ) {
 ngModel.$render = this._render.bind(this);
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}
 };
InputPersonController.prototype._makeWatch = function() {
 this._unwatch = this.$scope.$watchCollection(
 (function() {
 return this.value;
 }).bind(this),
 (function(newval, oldval) {
 if( newval !== oldval ) { // skip the initial trigger
 this._ngModel.$setViewValue(newval !== null ? new Person(newval) : null);
 }
 }).bind(this)
 );
 };
InputPersonController.prototype._render = function() {
 this._unwatch();
 this.value = this._ngModel.$viewValue ? new Person(this._ngModel.$viewValue) : null;
 this._makeWatch();
 };
return {
 restrict: 'E',
 scope: {},
 bindToController: true,
 controllerAs: 'ctrl',
 controller: InputPersonController,
 require: ['inputPerson', 'ngModel'],
 link: function(scope, elem, attrs, ctrls) {
 ctrls[0].setNgModel(ctrls[1]);
 },
 template:
 '<div>' +
 '<label><span>Name:</span><input type="text" ng-model="ctrl.value.name" /></label>'
+
 '<input-address ng-model="ctrl.value.address"></input-address>' +
 '</div>'
 };
});
Note: Here the objects are typed, i.e. they have proper constructors. This is not obligatory; the model can be plain
JSON objects. In this case just use angular.copy() instead of the constructors. An added advantage is that the
controller becomes identical for the two controls and can easily be extracted into some common module.
The fiddle: https://jsfiddle.net/3tzyqfko/2/
Two versions of the fiddle having extracted the common code of the controllers: https://jsfiddle.net/agj4cp0e/ and
https://jsfiddle.net/ugb6Lw8b/
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Chapter 14: Controllers
Section 14.1: Your First Controller
A controller is a basic structure used in Angular to preserve scope and handle certain actions within a page. Each
controller is coupled with an HTML view.
Below is a basic boilerplate for an Angular app:
<!DOCTYPE html>
<html lang="en" ng-app='MyFirstApp'>
 <head>
 <title>My First App</title>
<!-- angular source -->
 <script src="https://code.angularjs.org/1.5.3/angular.min.js"></script>
<!-- Your custom controller code -->
 <script src="js/controllers.js"></script>
 </head>
 <body>
 <div ng-controller="MyController as mc">
 <h1>{{ mc.title }}</h1>
 <p>{{ mc.description }}</p>
 <button ng-click="mc.clicked()">
 Click Me!
 </button>
 </div>
 </body>
</html>
There are a few things to note here:
<html ng-app='MyFirstApp'>
Setting the app name with ng-app lets you access the application in an external Javascript file, which will be covered
below.
<script src="js/controllers.js"></script>
We'll need a Javascript file where you define your controllers and their actions/data.
<div ng-controller="MyController as mc">
The ng-controller attribute sets the controller for that DOM element and all elements that are children
(recursively) below it.
You can have multiple of the same controller (in this case, MyController) by saying ... as mc, we're giving this
instance of the controller an alias.
<h1>{{ mc.title }}</h1>
The {{ ... }} notation is an Angular expression. In this case, this will set the inner text of that <h1> element to
whatever the value of mc.title is.
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Note: Angular employs dual-way data binding, meaning that regardless of how you update the mc.title value, it
will be reflected in both the controller and the page.
Also note that Angular expressions do not have to reference a controller. An Angular expression can be as simple as
{{ 1 + 2 }} or {{ "Hello " + "World" }}.
<button ng-click="mc.clicked()">
ng-click is an Angular directive, in this case binding the click event for the button to trigger the clicked() function
of the MyController instance.
With those things in mind, let's write an implementation of the MyController controller. With the example above,
you would write this code in js/controller.js.
First, you'll need to instantiate the Angular app in your Javascript.
var app = angular.module("MyFirstApp", []);
Note that the name we pass here is the same as the name you set in your HTML with the ng-app directive.
Now that we have the app object, we can use that to create controllers.
app.controller('MyController', function(){
 var ctrl = this;
ctrl.title = "My First Angular App";
 ctrl.description = "This is my first Angular app!";
ctrl.clicked = function(){
 alert("MyController.clicked()");
 };
});
Note: For anything that we want to be a part of the controller instance, we use the this keyword.
This is all that is required to build a simple controller.
Section 14.2: Creating Controllers, Minification safe
There are a couple different ways to protect your controller creation from minification.
The first is called inline array annotation. It looks like the following:
var app = angular.module('app');
app.controller('sampleController', ['$scope', '$http', function(a, b){
 //logic here
}]);
The second parameter of the controller method can accept an array of dependencies. As you can see I've defined
$scope and $http which should correspond to the parameters of the controller function in which a will be the
$scope, and b would be $http. Take note that the last item in the array should be your controller function.
The second option is using the $inject property. It looks like the following:
var app = angular.module('app');
app.controller('sampleController', sampleController);
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sampleController.$inject = ['$scope', '$http'];
function sampleController(a, b) {
 //logic here
}
This does the same thing as inline array annotation but provides a different styling for those that prefer one option
over the other.
The order of injected dependencies is important
When injecting dependencies using the array form, be sure that the list of the dependencies match its
corresponding list of arguments passed to the controller function.
Note that in the following example, $scope and $http are reversed. This will cause a problem in the code.
// Intentional Bug: injected dependencies are reversed which will cause a problem
app.controller('sampleController', ['$scope', '$http',function($http, $scope) {
 $http.get('sample.json');
}]);
Section 14.3: Using ControllerAs in Angular JS
In Angular $scope is the glue between the Controller and the View that helps with all of our data binding needs.
Controller As is another way of binding controller and view and is mostly recommended to use. Basically these are
the two controller constructs in Angular (i.e $scope and Controller As).
Different ways of using Controller As are -
controllerAs View Syntax
<div ng-controller="CustomerController as customer">
 {{ customer.name }}
</div>
controllerAs Controller Syntax
function CustomerController() {
 this.name = {};
 this.sendMessage = function() { };
}
controllerAs with vm
function CustomerController() {
 /*jshint validthis: true */
 var vm = this;
 vm.name = {};
 vm.sendMessage = function() { };
}
controllerAs is syntactic sugar over $scope. You can still bind to the View and still access $scope methods. Using
controllerAs, is one of the best practices suggested by the angular core team. There are many reason for this, few
of them are -
$scope is exposing the members from the controller to the view via an intermediary object. By setting
this.*, we can expose just what we want to expose from the controller to the view. It also follow the
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standard JavaScript way of using this.
using controllerAs syntax, we have more readable code and the parent property can be accessed using the
alias name of the parent controller instead of using the $parent syntax.
It promotes the use of binding to a "dotted" object in the View (e.g. customer.name instead of name), which
is more contextual, easier to read, and avoids any reference issues that may occur without "dotting".
Helps avoid using $parent calls in Views with nested controllers.
Use a capture variable for this when using the controllerAs syntax. Choose a consistent variable name such
as vm, which stands for ViewModel. Because, this keyword is contextual and when used within a function
inside a controller may change its context. Capturing the context of this avoids encountering this problem.
NOTE: using controllerAs syntax add to current scope reference to current controller, so it available as field
<div ng-controller="Controller as vm>...</div>
vm is available as $scope.vm.
Section 14.4: Creating Minification-Safe Angular Controllers
To create minification-safe angular controllers, you will change the controller function parameters.
The second argument in the module.controller function should be passed an array, where the last parameter is
the controller function, and every parameter before that is the name of each injected value.
This is different from the normal paradigm; that takes the controller function with the injected arguments.
Given:
var app = angular.module('myApp');
The controller should look like this:
app.controller('ctrlInject',
 [
 /* Injected Parameters */
 '$Injectable1',
 '$Injectable2',
 /* Controller Function */
 function($injectable1Instance, $injectable2Instance) {
 /* Controller Content */
 }
 ]
);
Note: The names of injected parameters are not required to match, but they will be bound in order.
This will minify to something similar to this:
var
a=angular.module('myApp');a.controller('ctrlInject',['$Injectable1','$Injectable2',function(b,c){/*
Controller Content */}]);
The minification process will replace every instance of app with a, every instance of $Injectable1Instance with b,
and every instance of $Injectable2Instance with c.
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Section 14.5: Creating Controllers
angular
 .module('app')
 .controller('SampleController', SampleController)
SampleController.$inject = ['$log', '$scope'];
function SampleController($log, $scope){
 $log.debug('*****SampleController******');
/* Your code below */
}
Note: The .$inject will make sure your dependencies doesn't get scrambled after minification. Also, make sure it's
in order with the named function.
Section 14.6: Nested Controllers
Nesting controllers chains the $scope as well. Changing a $scope variable in the nested controller changes the same
$scope variable in the parent controller.
.controller('parentController', function ($scope) {
 $scope.parentVariable = "I'm the parent";
});
.controller('childController', function ($scope) {
 $scope.childVariable = "I'm the child";
$scope.childFunction = function () {
 $scope.parentVariable = "I'm overriding you";
 };
});
Now let's try to handle both of them, nested.
<body ng-controller="parentController">
 What controller am I? {{parentVariable}}
 <div ng-controller="childController">
 What controller am I? {{childVariable}}
 <button ng-click="childFunction()"> Click me to override! </button>
 </div>
</body>
Nesting controllers may have it's benefits, but one thing must be kept in mind when doing so. Calling the
ngController directive creates a new instance of the controller - which can often create confusion and unexpected
results.
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Chapter 15: Controllers with ES6
Section 15.1: Controller
it is very easy to write an angularJS controller with ES6 if your are familiarized with the Object Oriented
Programming :
class exampleContoller{
constructor(service1,service2,...serviceN){
 let ctrl=this;
 ctrl.service1=service1;
 ctrl.service2=service2;
 .
 .
 .
 ctrl.service1=service1;
 ctrl.controllerName = 'Example Controller';
 ctrl.method1(controllerName)
}
method1(param){
 let ctrl=this;
 ctrl.service1.serviceFunction();
 .
 .
 ctrl.scopeName=param;
 }
 .
 .
 .
 methodN(param){
 let ctrl=this;
 ctrl.service1.serviceFunction();
 .
 .
 }
}
 exampleContoller.$inject = ['service1','service2',...,'serviceN'];
 export default exampleContoller;
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Chapter 16: The Self Or This Variable In A
Controller
This is an explanation of a common pattern and generally considered best practice that you may see in AngularJS
code.
Section 16.1: Understanding The Purpose Of The Self Variable
When using "controller as syntax" you would give your controller an alias in the html when using the ng-controller
directive.
<div ng-controller="MainCtrl as main">
</div>
You can then access properties and methods from the main variable that represents our controller instance. For
example, let's access the greeting property of our controller and display it on the screen:
<div ng-controller="MainCtrl as main">
 {{ main.greeting }}
</div>
Now, in our controller, we need to set a value to the greeting property of our controller instance (as opposed to
$scope or something else):
angular
.module('ngNjOrg')
.controller('ForgotPasswordController',function ($log) {
 var self = this;
self.greeting = "Hello World";
})
In order to have the HTML display correctly we needed to set the greeting property on this inside of our controller
body. I am creating an intermediate variable named self that holds a reference to this. Why? Consider this code:
angular
.module('ngNjOrg')
.controller('ForgotPasswordController',function ($log) {
 var self = this;
self.greeting = "Hello World";
function itsLate () {
 this.greeting = "Goodnight";
}
})
In this above code you may expect the text on the screen to update when the method itsLate is called, but in fact it
does not. JavaScript uses function level scoping rules so the "this" inside of itsLate refers to something different that
"this" outside of the method body. However, we can get the desired result if we use the self variable:
angular
.module('ngNjOrg')
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.controller('ForgotPasswordController',function ($log) {
 var self = this;
self.greeting = "Hello World";
function itsLate () {
 self.greeting = "Goodnight";
}
})
This is the beauty of using a "self" variable in your controllers- you can access this anywhere in your controller and
can always be sure that it is referencing your controller instance.
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Chapter 17: Services
Section 17.1: Creating a service using angular.factory
First define the service (in this case it uses the factory pattern):
.factory('dataService', function() {
 var dataObject = {};
 var service = {
 // define the getter method
 get data() {
 return dataObject;
 },
 // define the setter method
 set data(value) {
 dataObject = value || {};
 }
 };
 // return the "service" object to expose the getter/setter
 return service;
})
Now you can use the service to share data between controllers:
.controller('controllerOne', function(dataService) {
 // create a local reference to the dataService
 this.dataService = dataService;
 // create an object to store
 var someObject = {
 name: 'SomeObject',
 value: 1
 };
 // store the object
 this.dataService.data = someObject;
})
.controller('controllerTwo', function(dataService) {
 // create a local reference to the dataService
 this.dataService = dataService;
 // this will automatically update with any changes to the shared data object
 this.objectFromControllerOne = this.dataService.data;
})
Section 17.2: Dierence between Service and Factory
1) Services
A service is a constructor function that is invoked once at runtime with new, just like what we would do with plain
JavaScript with only difference that AngularJS is calling the new behind the scenes.
There is one thumb rule to remember in case of services
1.
Services are constructors which are called with new
Lets see a simple example where we would register a service which uses $http service to fetch student details, and
use it in the controller
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function StudentDetailsService($http) {
 this.getStudentDetails = function getStudentDetails() {
 return $http.get('/details');
 };
}
angular.module('myapp').service('StudentDetailsService', StudentDetailsService);
We just inject this service into the controller
function StudentController(StudentDetailsService) {
 StudentDetailsService.getStudentDetails().then(function (response) {
 // handle response
 });
}
angular.module('app').controller('StudentController', StudentController);
When to use?
Use .service() wherever you want to use a constructor. It is usually used to create public API's just like
getStudentDetails(). But if you don't want to use a constructor and wish to use a simple API pattern instead, then
there isn't much flexibility in .service().
2) Factory
Even though we can achieve all the things using .factory() which we would, using .services(), it doesn't make
.factory() "same as" .service(). It is much more powerful and flexible than .service()
A .factory() is a design pattern which is used to return a value.
There are two thumb rules to remember in case of factories
1.
2.
Factories return values
Factories (can) create objects (Any object)
Lets see some examples on what we can do using .factory()
Returning Objects Literals
Lets see an example where factory is used to return an object using a basic Revealing module pattern
function StudentDetailsService($http) {
 function getStudentDetails() {
 return $http.get('/details');
 }
 return {
 getStudentDetails: getStudentDetails
 };
}
angular.module('myapp').factory('StudentDetailsService', StudentDetailsService);
Usage inside a controller
function StudentController(StudentDetailsService) {
 StudentDetailsService.getStudentDetails().then(function (response) {
 // handle response
 });
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}
angular.module('app').controller('StudentController', StudentController);
Returning Closures
What is a closure?
Closures are functions that refer to variables that are used locally, BUT defined in an enclosing scope.
Following is an example of a closure
function closureFunction(name) {
 function innerClosureFunction(age) { // innerClosureFunction() is the inner function, a closure
 // Here you can manipulate 'age' AND 'name' variables both
 };
};
The "wonderful" part is that it can access the name which is in the parent scope.
Lets use the above closure example inside .factory()
function StudentDetailsService($http) {
 function closureFunction(name) {
 function innerClosureFunction(age) {
 // Here you can manipulate 'age' AND 'name' variables
 };
 };
};
angular.module('myapp').factory('StudentDetailsService', StudentDetailsService);
Usage inside a controller
function StudentController(StudentDetailsService) {
 var myClosure = StudentDetailsService('Student Name'); // This now HAS the innerClosureFunction()
 var callMyClosure = myClosure(24); // This calls the innerClosureFunction()
};
angular.module('app').controller('StudentController', StudentController);
Creating Constructors/instances
.service() creates constructors with a call to new as seen above. .factory() can also create constructors with a
call to new
Lets see an example on how to achieve this
function StudentDetailsService($http) {
 function Student() {
 this.age = function () {
 return 'This is my age';
 };
 }
 Student.prototype.address = function () {
 return 'This is my address';
 };
 return Student;
};
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angular.module('myapp').factory('StudentDetailsService', StudentDetailsService);
Usage inside a controller
function StudentController(StudentDetailsService) {
 var newStudent = new StudentDetailsService();
//Now the instance has been created. Its properties can be accessed.
newStudent.age();
 newStudent.address();
};
angular.module('app').controller('StudentController', StudentController);
Section 17.3: $sce - sanitize and render content and resources
in templates
$sce ("Strict Contextual Escaping") is a built-in angular service that automatically sanitize content and
internal sources in templates.
injecting external sources and raw HTML into the template requires manual wrapping of$sce.
In this example we'll create a simple $sce sanitation filter :`.
Demo
.filter('sanitizer', ['$sce', [function($sce) {
 return function(content) {
 return $sce.trustAsResourceUrl(content);
 };
}]);
Usage in template
<div ng-repeat="item in items">
// Sanitize external sources
 <ifrmae ng-src="{{item.youtube_url | sanitizer}}">
// Sanitaize and render HTML
 <div ng-bind-html="{{item.raw_html_content| sanitizer}}"></div>
</div>
Section 17.4: How to create a Service
angular.module("app")
 .service("counterService", function(){
var service = {
 number: 0
 };
return service;
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});
Section 17.5: How to use a service
angular.module("app")
// Custom services are injected just like Angular's built-in services
 .controller("step1Controller", ['counterService', '$scope', function(counterService,
$scope) {
 counterService.number++;
 // bind to object (by reference), not to value, for automatic sync
 $scope.counter = counterService;
 })
In the template using this controller you'd then write:
// editable
<input ng-model="counter.number" />
or
// read-only
<span ng-bind="counter.number"></span>
Of course, in real code you would interact with the service using methods on the controller, which in turn delegate
to the service. The example above simply increments the counter value each time the controller is used in a
template.
Services in Angularjs are singletons:
Services are singleton objects that are instantiated only once per app (by the $injector) and lazy loaded (created
only when necessary).
A singleton is a class which only allows one instance of itself to be created - and gives simple, easy access
to said instance. As stated here
Section 17.6: How to create a Service with dependencies using
'array syntax'
angular.module("app")
 .service("counterService", ["fooService", "barService", function(anotherService, barService){
var service = {
 number: 0,
 foo: function () {
 return fooService.bazMethod(); // Use of 'fooService'
 },
 bar: function () {
 return barService.bazMethod(); // Use of 'barService'
 }
 };
return service;
 }]);
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Section 17.7: Registering a Service
The most common and flexible way to create a service uses the angular.module API factory:
angular.module('myApp.services', []).factory('githubService', function() {
var serviceInstance = {};
 // Our first service
 return serviceInstance;
});
The service factory function can be either a function or an array, just like the way we create controllers:
// Creating the factory through using the
// bracket notation
angular.module('myApp.services', [])
.factory('githubService', [function($http) {
}]);
To expose a method on our service, we can place it as an attribute on the service object.
angular.module('myApp.services', [])
 .factory('githubService', function($http) {
 var githubUrl = 'https://api.github.com';
 var runUserRequest = function(username, path) {
 // Return the promise from the $http service
 // that calls the Github API using JSONP
 return $http({
 method: 'JSONP',
 url: githubUrl + '/users/' +
 username + '/' +
 path + '?callback=JSON_CALLBACK'
 });
 }
// Return the service object with a single function
// events
return {
 events: function(username) {
 return runUserRequest(username, 'events');
 }
};
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Chapter 18: Distinguishing Service vs
Factory
Section 18.1: Factory VS Service once-and-for-all
By definition:
Services are basically constructor functions. They use ‘this’ keyword.
Factories are simple functions hence return an object.
Under the hood:
Factories internally calls provider function.
Services internally calls Factory function.
Debate:
Factories can run code before we return our object literal.
But at the same time, Services can also be written to return an object literal and to run code before returning.
Though that is contra productive as services are designed to act as constructor function.
In fact, constructor functions in JavaScript can return whatever they want.
So which one is better?
The constructor syntax of services is more close to class syntax of ES6. So migration will be easy.
Summary
So in summary, provider, factory, and service are all providers.
A factory is a special case of a provider when all you need in your provider is a $get() function. It allows you to write
it with less code.
A service is a special case of a factory when you want to return an instance of a new object, with the same benefit of
writing less code.
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Chapter 19: Angular promises with $q
service
Section 19.1: Wrap simple value into a promise using $q.when()
If all you need is to wrap the value into a promise, you don't need to use the long syntax like here:
//OVERLY VERBOSE
var defer;
defer = $q.defer();
defer.resolve(['one', 'two']);
return defer.promise;
In this case you can just write:
//BETTER
return $q.when(['one', 'two']);
$q.when and its alias $q.resolve
Wraps an object that might be a value or a (3rd party) then-able promise into a $q promise. This is useful
when you are dealing with an object that might or might not be a promise, or if the promise comes from
a source that can't be trusted.
— AngularJS $q Service API Reference - $q.when
With the release of AngularJS v1.4.1
You can also use an ES6-consistent alias resolve
//ABSOLUTELY THE SAME AS when
return $q.resolve(['one', 'two'])
Section 19.2: Using angular promises with $q service
$q is a built-in service which helps in executing asynchronous functions and using their return values(or exception)
when they are finished with processing.
$q is integrated with the $rootScope.Scope model observation mechanism, which means faster propagation of
resolution or rejection into your models and avoiding unnecessary browser repaints, which would result in
flickering UI.
In our example, we call our factory getMyData, which return a promise object. If the object is resolved, it returns a
random number. If it is rejected, it return a rejection with an error message after 2 seconds.
In Angular factory
function getMyData($timeout, $q) {
 return function() {
 // simulated async function
 var promise = $timeout(function() {
 if(Math.round(Math.random())) {
 return 'data received!'
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} else {
 return $q.reject('oh no an error! try again')
 }
 }, 2000);
 return promise;
 }
}
Using Promises on call
angular.module('app', [])
.factory('getMyData', getMyData)
.run(function(getData) {
 var promise = getData()
 .then(function(string) {
 console.log(string)
 }, function(error) {
 console.error(error)
 })
 .finally(function() {
 console.log('Finished at:', new Date())
 })
})
To use promises, inject $q as dependency. Here we injected $q in getMyData factory.
var defer = $q.defer();
A new instance of deferred is constructed by calling $q.defer()
A deferred object is simply an object that exposes a promise as well as the associated methods for resolving that
promise. It is constructed using the $q.deferred() function and exposes three main methods: resolve(),
reject(), and notify().
resolve(value) – resolves the derived promise with the value.
reject(reason) – rejects the derived promise with the reason.
notify(value) - provides updates on the status of the promise's execution. This may be called multiple
times before the promise is either resolved or rejected.
Properties
The associated promise object is accessed via the promise property. promise – {Promise} – promise object
associated with this deferred.
A new promise instance is created when a deferred instance is created and can be retrieved by calling
deferred.promise.
The purpose of the promise object is to allow for interested parties to get access to the result of the deferred task
when it completes.
Promise Methods -
then(successCallback, [errorCallback], [notifyCallback]) – Regardless of when the promise was or
will be resolved or rejected, then calls one of the success or error callbacks asynchronously as soon as the
result is available. The callbacks are called with a single argument: the result or rejection reason. Additionally,
the notify callback may be called zero or more times to provide a progress indication, before the promise is
resolved or rejected.
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catch(errorCallback) – shorthand for promise.then(null, errorCallback)
finally(callback, notifyCallback) – allows you to observe either the fulfillment or rejection of a promise,
but to do so without modifying the final value.
One of the most powerful features of promises is the ability to chain them together. This allows the data to flow
through the chain and be manipulated and mutated at each step. This is demonstrated with the following example:
Example 1:
// Creates a promise that when resolved, returns 4.
function getNumbers() {
var promise = $timeout(function() {
 return 4;
 }, 1000);
return promise;
}
// Resolve getNumbers() and chain subsequent then() calls to decrement
// initial number from 4 to 0 and then output a string.
getNumbers()
 .then(function(num) {
 // 4
 console.log(num);
 return --num;
 })
 .then(function (num) {
 // 3
 console.log(num);
 return --num;
 })
 .then(function (num) {
 // 2
 console.log(num);
 return --num;
 })
 .then(function (num) {
 // 1
 console.log(num);
 return --num;
 })
 .then(function (num) {
 // 0
 console.log(num);
 return 'And we are done!';
 })
 .then(function (text) {
 // "And we are done!"
 console.log(text);
});
Section 19.3: Using the $q constructor to create promises
The $q constructor function is used to create promises from asynchronous APIs that use callbacks to return results.
$q(function(resolve, reject) {...})
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The constructor function receives a function that is invoked with two arguments, resolve and reject that are
functions which are used to either resolve or reject the promise.
Example 1:
function $timeout(fn, delay) {
 return = $q(function(resolve, reject) {
 setTimeout(function() {
 try {
 let r = fn();
 resolve(r);
 }
 catch (e) {
 reject(e);
 }
 }, delay);
 };
}
The above example creates a promise from the WindowTimers.setTimeout API. The AngularJS framework provides
a more elaborate version of this function. For usage, see the AngularJS $timeout Service API Reference.
Example 2:
$scope.divide = function(a, b) {
 return $q(function(resolve, reject) {
 if (b===0) {
 return reject("Cannot devide by 0")
 } else {
 return resolve(a/b);
 }
 });
}
The above code showing a promisified division function, it will return a promise with the result or reject with a
reason if the calculation is impossible.
You can then call and use .then
$scope.divide(7, 2).then(function(result) {
 // will return 3.5
}, function(err) {
 // will not run
})
$scope.divide(2, 0).then(function(result) {
 // will not run as the calculation will fail on a divide by 0
}, function(err) {
 // will return the error string.
})
Section 19.4: Avoid the $q Deferred Anti-Pattern
Avoid this Anti-Pattern
var myDeferred = $q.defer();
$http(config).then(function(res) {
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myDeferred.resolve(res);
}, function(error) {
 myDeferred.reject(error);
});
return myDeferred.promise;
There is no need to manufacture a promise with $q.defer as the $http service already returns a promise.
//INSTEAD
return $http(config);
Simply return the promise created by the $http service.
Section 19.5: Using $q.all to handle multiple promises
You can use the $q.all function to call a .then method after an array of promises has been successfully resolved
and fetch the data they resolved with.
Example:
JS:
$scope.data = []
$q.all([
 $http.get("data.json"),
 $http.get("more-data.json"),
 ]).then(function(responses) {
 $scope.data = responses.map((resp) => resp.data);
 });
The above code runs $http.get 2 times for data in local json files, when both get method complete they resolve
their associated promises, when all the promises in the array are resolved, the .then method starts with both
promises data inside the responses array argument.
The data is then mapped so it could be shown on the template, we can then show
HTML:
<ul>
 <li ng-repeat="d in data">
 <ul>
 <li ng-repeat="item in d">{{item.name}}: {{item.occupation}}</li>
 </ul>
 </li>
</ul>
JSON:
[{
 "name": "alice",
 "occupation": "manager"
}, {
 "name": "bob",
 "occupation": "developer"
}]
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Section 19.6: Deferring operations using $q.defer
We can use $q to defer operations to the future while having a pending promise object at the present, by using
$q.defer we create a promise that will either resolve or reject in the future.
This method is not equivalent of using the $q constructor, as we use $q.defer to promisify an existing routine that
may or may not return (or had ever returned) a promise at all.
Example:
var runAnimation = function(animation, duration) {
 var deferred = $q.defer();
 try {
 ...
 // run some animation for a given duration
 deferred.resolve("done");
 } catch (err) {
 // in case of error we would want to run the error hander of .then
 deferred.reject(err);
 }
 return deferred.promise;
}
// and then
runAnimation.then(function(status) {}, function(error) {})
1.
Be sure you always return a the deferred.promise object or risk an error when invoking .then
2.
Make sure you always resolve or reject your deferred object or .then may not run and you risk a memory
leak
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Chapter 20: Dependency Injection
Section 20.1: Dynamic Injections
There is also an option to dynamically request components. You can do it using the $injector service:
myModule.controller('myController', ['$injector', function($injector) {
 var myService = $injector.get('myService');
}]);
Note: while this method could be used to prevent the circular dependency issue that might break your app, it is not
considered best practice to bypass the problem by using it. Circular dependency usually indicates there is a flaw in
your application's architecture, and you should address that instead.
Section 20.2: Dynamically load AngularJS service in vanilla
JavaScript
You can load AngularJS services in vanilla JavaScript using AngularJS injector() method. Every jqLite element
retrieved calling angular.element() has a method injector() that can be used to retrieve the injector.
var service;
var serviceName = 'myService';
var ngAppElement = angular.element(document.querySelector('[ng-app],[data-ng-app]') || document);
var injector = ngAppElement.injector();
if(injector && injector.has(serviceNameToInject)) {
 service = injector.get(serviceNameToInject);
}
In the above example we try to retrieve the jqLite element containing the root of the AngularJS application
(ngAppElement). To do that, we use angular.element() method, searching for a DOM element containing ng-app or
data-ng-app attribute or, if it does not exists, we fall back to document element. We use ngAppElement to retrieve
injector instance (with ngAppElement.injector()). The injector instance is used to check if the service to inject
exists (with injector.has()) and then to load the service (with injector.get()) inside service variable.
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Chapter 21: Events
Parameters
event
Values types
Object {name: "eventName", targetScope: Scope, defaultPrevented: false, currentScope: ChildScope}
args
data that has been passed along with event execution
Section 21.1: Using angular event system
$scope.$emit
Using $scope.$emit will fire an event name upwards through the scope hierarchy and notify to the $scope.The
event life cycle starts at the scope on which $emit was called.
Working wireframe :
$scope.$broadcast
Using $scope.$broadcast will fire an event down the $scope. We can listen of these events using $scope.$on
Working wireframe :
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Syntax :
// firing an event upwards
$scope.$emit('myCustomEvent', 'Data to send');
// firing an event downwards
$scope.$broadcast('myCustomEvent', {
 someProp: 'some value'
});
// listen for the event in the relevant $scope
$scope.$on('myCustomEvent', function (event, data) {
 console.log(data); // 'Data from the event'
});
Instead of $scope you can use $rootScope, in that case your event will be available in all the controllers regardless
of that controllers scope
Clean registered event in AngularJS
The reason to clean the registered events because even the controller has been destroyed the handling of
registered event are still alive. So the code will run as unexpected for sure.
// firing an event upwards
$rootScope.$emit('myEvent', 'Data to send');
// listening an event
var listenerEventHandler = $rootScope.$on('myEvent', function(){
 //handle code
});
$scope.$on('$destroy', function() {
 listenerEventHandler();
});
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Section 21.2: Always deregister $rootScope.$on listeners on
the scope $destory event
$rootScope.$on listeners will remain in memory if you navigate to another controller. This will create a memory
leak if the controller falls out of scope.
Don't
angular.module('app').controller('badExampleController', badExample);
badExample.$inject = ['$scope', '$rootScope'];
function badExample($scope, $rootScope) {
$rootScope.$on('post:created', function postCreated(event, data) {});
}
Do
angular.module('app').controller('goodExampleController', goodExample);
goodExample.$inject = ['$scope', '$rootScope'];
function goodExample($scope, $rootScope) {
var deregister = $rootScope.$on('post:created', function postCreated(event, data) {});
$scope.$on('$destroy', function destroyScope() {
 deregister();
 });
}
Section 21.3: Uses and significance
These events can be used to communicate between 2 or more controllers.
$emit dispatches an event upwards through the scope hierarchy, while $broadcast dispatches an event downwards
to all child scopes.This has been beautifully explained here.
There can be basically two types of scenario while communicating among controllers:
1.
When controllers have Parent-Child relationship. (we can mostly use $scope in such scenarios)
2.
When controllers are not independent to each other and are needed to be informed about each others
activity. (we can use $rootScope in such scenarios)
eg: For any ecommerce website, suppose we have ProductListController(which controls the product listing page
when any product brand is clicked ) and CartController (to manage cart items) . Now, when we click on Add to
Cart button , it has to be informed to CartController as well, so that it can reflect new cart item count/details in
the navigation bar of the website. This can be achieved using $rootScope.
With $scope.$emit
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<html>
 <head>
 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.4/angular.js"></script>
 <script>
 var app = angular.module('app', []);
app.controller("FirstController", function ($scope) {
 $scope.$on('eventName', function (event, args) {
 $scope.message = args.message;
 });
 });
app.controller("SecondController", function ($scope) {
 $scope.handleClick = function (msg) {
 $scope.$emit('eventName', {message: msg});
 };
 });
</script>
 </head>
 <body ng-app="app">
 <div ng-controller="FirstController" style="border:2px ;padding:5px;">
 <h1>Parent Controller</h1>
 <p>Emit Message : {{message}}</p>
 <br />
 <div ng-controller="SecondController" style="border:2px;padding:5px;">
 <h1>Child Controller</h1>
 <input ng-model="msg">
 <button ng-click="handleClick(msg);">Emit</button>
 </div>
 </div>
 </body>
</html>
With $scope.$broadcast:
<html>
 <head>
 <title>Broadcasting</title>
 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.4/angular.js"></script>
 <script>
 var app = angular.module('app', []);
app.controller("FirstController", function ($scope) {
 $scope.handleClick = function (msg) {
 $scope.$broadcast('eventName', {message: msg});
 };
});
app.controller("SecondController", function ($scope) {
 $scope.$on('eventName', function (event, args) {
 $scope.message = args.message;
 });
 });
</script>
 </head>
 <body ng-app="app">
 <div ng-controller="FirstController" style="border:2px solid ; padding:5px;">
 <h1>Parent Controller</h1>
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<input ng-model="msg">
 <button ng-click="handleClick(msg);">Broadcast</button>
 <br /><br />
 <div ng-controller="SecondController" style="border:2px solid ;padding:5px;">
 <h1>Child Controller</h1>
 <p>Broadcast Message : {{message}}</p>
 </div>
 </div>
 </body>
</html>
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Chapter 22: Sharing Data
Section 22.1: Using ngStorage to share data
Firstly, include the ngStorage source in your index.html.
An example injecting ngStorage src would be:
<head>
 <title>Angular JS ngStorage</title>
 <script src = "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
 <script src="https://rawgithub.com/gsklee/ngStorage/master/ngStorage.js"></script>
</head>
ngStorage gives you 2 storage namely: $localStorage and $sessionStorage. You need to require ngStorage and
Inject the services.
Suppose if ng-app="myApp", then you would be injecting ngStorage as following:
var app = angular.module('myApp', ['ngStorage']);
 app.controller('controllerOne', function($localStorage,$sessionStorage) {
 // an object to share
 var sampleObject = {
 name: 'angularjs',
 value: 1
 };
 $localStorage.valueToShare = sampleObject;
 $sessionStorage.valueToShare = sampleObject;
 })
.controller('controllerTwo', function($localStorage,$sessionStorage) {
 console.log('localStorage: '+ $localStorage +'sessionStorage: '+$sessionStorage);
})
$localStorage and $sessionStorage is globally accessible through any controllers as long as you inject those
services in the controllers.
You can also use the localStorage and sessionStorage of HTML5. However, using HTML5 localStorage would
require you to serialize and deserialize your objects before using or saving them.
For example:
var myObj = {
 firstname: "Nic",
 lastname: "Raboy",
 website: "https://www.google.com"
}
//if you wanted to save into localStorage, serialize it
window.localStorage.set("saved", JSON.stringify(myObj));
//unserialize to get object
var myObj = JSON.parse(window.localStorage.get("saved"));
Section 22.2: Sharing data from one controller to another
using service
We can create a service to set and get the data between the controllers and then inject that service in the
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controller function where we want to use it.
Service :
app.service('setGetData', function() {
 var data = '';
 getData: function() { return data; },
 setData: function(requestData) { data = requestData; }
});
Controllers :
app.controller('myCtrl1', ['setGetData',function(setGetData) {
// To set the data from the one controller
 var data = 'Hello World !!';
setGetData.setData(data);
}]);
app.controller('myCtrl2', ['setGetData',function(setGetData) {
// To get the data from the another controller
var res = setGetData.getData();
 console.log(res); // Hello World !!
}]);
Here, we can see that myCtrl1 is used for setting the data and myCtrl2 is used for getting the data. So, we can
share the data from one controller to another contrller like this.
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Chapter 23: Form Validation
Section 23.1: Form and Input States
Angular Forms and Inputs have various states that are useful when validating content
Input States
State
$touched
Description
Field has been touched
$untouched Field has not been touched
$pristine Field has not been modified
$dirty
$valid
Field has been modified
Field content is valid
$invalid
Field content is invalid
All of the above states are boolean properties and can be either true or false.
With these, it is very easy to display messages to a user.
<form name="myForm" novalidate>
 <input name="myName" ng-model="myName" required>
 <span ng-show="myForm.myName.$touched && myForm.myName.$invalid">This name is invalid</span>
</form>
Here, we are using the ng-show directive to display a message to a user if they've modified a form but it's invalid.
Section 23.2: CSS Classes
Angular also provides some CSS classes for forms and inputs depending on their state
Class
Description
ng-touched
Field has been touched
ng-untouched Field has not been touched
ng-pristine Field has not been modified
ng-dirty
Field has been modified
ng-valid
Field is valid
ng-invalid
Field is invalid
You can use these classes to add styles to your forms
input.ng-invalid {
 background-color: crimson;
}
input.ng-valid {
 background-color: green;
}
Section 23.3: Basic Form Validation
One of Angular's strength's is client-side form validation.
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Dealing with traditional form inputs and having to use interrogative jQuery-style processing can be time-consuming
and finicky. Angular allows you to produce professional interactive forms relatively easily.
The ng-model directive provides two-way binding with input fields and usually the novalidate attribute is also
placed on the form element to prevent the browser from doing native validation.
Thus, a simple form would look like:
<form name="form" novalidate>
 <label name="email"> Your email </label>
 <input type="email" name="email" ng-model="email" />
</form>
For Angular to validate inputs, use exactly the same syntax as a regular input element, except for the addition of the
ng-model attribute to specify which variable to bind to on the scope. Email is shown in the prior example. To
validate a number, the syntax would be:
<input type="number" name="postalcode" ng-model="zipcode" />
The final steps to basic form validation are connecting to a form submit function on the controller using ng-submit,
rather than allowing the default form submit to occur. This is not mandatory but it is usually used, as the input
variables are already available on the scope and so available to your submit function. It is also usually good practice
to give the form a name. These changes would result in the following syntax:
<form name="signup_form" ng-submit="submitFunc()" novalidate>
 <label name="email"> Your email </label>
 <input type="email" name="email" ng-model="email" />
 <button type="submit">Signup</button>
</form>
This above code is functional but there is other functionality that Angular provides.
The next step is to understand that Angular attaches class attributes using ng-pristine, ng-dirty, ng-valid and ng-
invalid for form processing. Using these classes in your css will allow you to style valid/invalid and pristine/dirty
input fields and so alter the presentation as the user is entering data into the form.
Section 23.4: Custom Form Validation
In some cases basic validation is not enough. Angular support custom validation adding validator functions to the
$validators object on the ngModelController:
angular.module('app', [])
 .directive('myValidator', function() {
 return {
 // element must have ng-model attribute
 // or $validators does not work
 require: 'ngModel',
 link: function(scope, elm, attrs, ctrl) {
 ctrl.$validators.myValidator = function(modelValue, viewValue) {
 // validate viewValue with your custom logic
 var valid = (viewValue && viewValue.length > 0) || false;
 return valid;
 };
 }
 };
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The validator is defined as a directive that require ngModel, so to apply the validator just add the custom directive to
the input form control.
<form name="form">
 <input type="text"
 ng-model="model"
 name="model"
 my-validator>
 <pre ng-bind="'my-validator returned: ' + form.model.$valid"></pre>
</form>
And my-validator doesn't have to be applied on native form control. It can be any elements, as long as it as ng-
model in its attributes. This is useful when you have some custom build ui component.
Section 23.5: Async validators
Asynchronous validators allows you to validate form information against your backend (using $http).
These kind of validators are needed when you need to access server stored information you can't have on your
client for various reasons, such as the users table and other database information.
To use async validators, you access the ng-model of your input and define callback functions for the
$asyncValidators property.
Example:
The following example checks if a provided name already exists, the backend will return a status that will reject the
promise if the name already exists or if it wasn't provided. If the name doesn't exist it will return a resolved
promise.
ngModel.$asyncValidators.usernameValidate = function (name) {
if (name) {
 return AuthenticationService.checkIfNameExists(name); // returns a promise
 } else {
 return $q.reject("This username is already taken!"); // rejected promise
 }
};
Now every time the ng-model of the input is changed, this function will run and return a promise with the result.
Section 23.6: ngMessages
ngMessages is used to enhanced the style for displaying validation messages in the view.
Traditional approach
Before ngMessages, we normally display the validation messages using Angular pre-defined directives ng-class.This
approach was litter and a repetitive task.
Now, by using ngMessages we can create our own custom messages.
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Example
HTML:
<form name="ngMessagesDemo">
 <input name="firstname" type="text" ng-model="firstname" required>
 <div ng-messages="ngMessagesDemo.firstname.$error">
 <div ng-message="required">Firstname is required.</div>
 </div>
</form>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.3.16/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.3.16/angular-
messages.min.js"></script>
JS:
var app = angular.module('app', ['ngMessages']);
app.controller('mainCtrl', function ($scope) {
 $scope.firstname = "Rohit";
});
Section 23.7: Nested Forms
Sometimes it is desirable to nest forms for the purpose of grouping controls and inputs logically on the page.
However, HTML5 forms should not be nested. Angular supplies ng-form instead.
<form name="myForm" noValidate>
 <!-- nested form can be referenced via 'myForm.myNestedForm' -->
 <ng-form name="myNestedForm" noValidate>
 <input name="myInput1" ng-minlength="1" ng-model="input1" required />
 <input name="myInput2" ng-minlength="1" ng-model="input2" required />
 </ng-form>
<!-- show errors for the nested subform here -->
 <div ng-messages="myForm.myNestedForm.$error">
 <!-- note that this will show if either input does not meet the minimum -->
 <div ng-message="minlength">Length is not at least 1</div>
 </div>
</form>
<!-- status of the form -->
<p>Has any field on my form been edited? {{myForm.$dirty}}</p>
<p>Is my nested form valid? {{myForm.myNestedForm.$valid}}</p>
<p>Is myInput1 valid? {{myForm.myNestedForm.myInput1.$valid}}</p>
Each part of the form contributes to the overall form's state. Therefore, if one of the inputs myInput1 has been
edited and is $dirty, its containing form will also be $dirty. This cascades to each containing form, so both
myNestedForm and myForm will be $dirty.
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Chapter 24: Routing using ngRoute
Section 24.1: Basic example
This example shows setting up a small application with 3 routes, each with it's own view and controller, using the
controllerAs syntax.
We configure our router at the angular .config function
We inject $routeProvider into .config
We define our route names at the .when method with a route definition object.
We supply the .when method with an object specifying our template or templateUrl, controller and
controllerAs
1.
2.
3.
app.js
angular.module('myApp', ['ngRoute'])
 .controller('controllerOne', function() {
 this.message = 'Hello world from Controller One!';
 })
 .controller('controllerTwo', function() {
 this.message = 'Hello world from Controller Two!';
 })
 .controller('controllerThree', function() {
 this.message = 'Hello world from Controller Three!';
 })
 .config(function($routeProvider) {
 $routeProvider
 .when('/one', {
 templateUrl: 'view-one.html',
 controller: 'controllerOne',
 controllerAs: 'ctrlOne'
 })
 .when('/two', {
 templateUrl: 'view-two.html',
 controller: 'controllerTwo',
 controllerAs: 'ctrlTwo'
 })
 .when('/three', {
 templateUrl: 'view-three.html',
 controller: 'controllerThree',
 controllerAs: 'ctrlThree'
 })
 // redirect to here if no other routes match
 .otherwise({
 redirectTo: '/one'
 });
 });
Then in our HTML we define our navigation using <a> elements with href, for a route name of helloRoute we will
route as <a href="#/helloRoute">My route</a>
We also provide our view with a container and the directive ng-view to inject our routes.
index.html
<div ng-app="myApp">
 <nav>
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<!-- links to switch routes -->
 <a href="#/one">View One</a>
 <a href="#/two">View Two</a>
 <a href="#/three">View Three</a>
 </nav>
 <!-- views will be injected here -->
 <div ng-view></div>
 <!-- templates can live in normal html files -->
 <script type="text/ng-template" id="view-one.html">
 <h1>{{ctrlOne.message}}</h1>
 </script>
<script type="text/ng-template" id="view-two.html">
 <h1>{{ctrlTwo.message}}</h1>
 </script>
<script type="text/ng-template" id="view-three.html">
 <h1>{{ctrlThree.message}}</h1>
 </script>
</div>
Section 24.2: Defining custom behavior for individual routes
The simplest manner of defining custom behavior for individual routes would be fairly easy.
In this example we use it to authenticate a user :
1) routes.js: create a new property (like requireAuth) for any desired route
angular.module('yourApp').config(['$routeProvider', function($routeProvider) {
 $routeProvider
 .when('/home', {
 templateUrl: 'templates/home.html',
 requireAuth: true
 })
 .when('/login', {
 templateUrl: 'templates/login.html',
 })
 .otherwise({
 redirectTo: '/home'
 });
}])
2) In a top-tier controller that isn't bound to an element inside the ng-view (to avoid conflict with angular
$routeProvider), check if the newUrl has the requireAuth property and act accordingly
angular.module('YourApp').controller('YourController', ['$scope', 'session', '$location',
 function($scope, session, $location) {
$scope.$on('$routeChangeStart', function(angularEvent, newUrl) {
if (newUrl.requireAuth && !session.user) {
 // User isn’t authenticated
 $location.path("/login");
 }
});
 }
]);
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Section 24.3: Route parameters example
This example extends the basic example passing parameters in the route in order to use them in the controller
To do so we need to:
Configure the parameter position and name in the route name
Inject $routeParams service in our Controller
1.
2.
app.js
angular.module('myApp', ['ngRoute'])
 .controller('controllerOne', function() {
 this.message = 'Hello world from Controller One!';
 })
 .controller('controllerTwo', function() {
 this.message = 'Hello world from Controller Two!';
 })
 .controller('controllerThree', ['$routeParams', function($routeParams) {
 var routeParam = $routeParams.paramName
if ($routeParams.message) {
 // If a param called 'message' exists, we show it's value as the message
 this.message = $routeParams.message;
 } else {
 // If it doesn't exist, we show a default message
 this.message = 'Hello world from Controller Three!';
 }
 }])
 .config(function($routeProvider) {
 $routeProvider
 .when('/one', {
 templateUrl: 'view-one.html',
 controller: 'controllerOne',
 controllerAs: 'ctrlOne'
 })
 .when('/two', {
 templateUrl: 'view-two.html',
 controller: 'controllerTwo',
 controllerAs: 'ctrlTwo'
 })
 .when('/three', {
 templateUrl: 'view-three.html',
 controller: 'controllerThree',
 controllerAs: 'ctrlThree'
 })
 .when('/three/:message', { // We will pass a param called 'message' with this route
 templateUrl: 'view-three.html',
 controller: 'controllerThree',
 controllerAs: 'ctrlThree'
 })
 // redirect to here if no other routes match
 .otherwise({
 redirectTo: '/one'
 });
 });
Then, withoud making any changes in our templates, only adding a new link with custom message, we can see the
new custom message in our view.
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index.html
<div ng-app="myApp">
 <nav>
 <!-- links to switch routes -->
 <a href="#/one">View One</a>
 <a href="#/two">View Two</a>
 <a href="#/three">View Three</a>
 <!-- New link with custom message -->
 <a href="#/three/This-is-a-message">View Three with "This-is-a-message" custom message</a>
 </nav>
 <!-- views will be injected here -->
 <div ng-view></div>
 <!-- templates can live in normal html files -->
 <script type="text/ng-template" id="view-one.html">
 <h1>{{ctrlOne.message}}</h1>
 </script>
<script type="text/ng-template" id="view-two.html">
 <h1>{{ctrlTwo.message}}</h1>
 </script>
<script type="text/ng-template" id="view-three.html">
 <h1>{{ctrlThree.message}}</h1>
 </script>
</div>
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Chapter 25: ng-class directive
Section 25.1: Three types of ng-class expressions
Angular supports three types of expressions in the ng-class directive.
1. String
<span ng-class="MyClass">Sample Text</span>
Specifying an expression that evaluates to a string tells Angular to treat it as a $scope variable. Angular will check
the $scope and look for a variable called "MyClass". Whatever text is contained in "MyClass" will become the actual
class name that is applied to this <span>. You can specify multiple classes by separating each class with a space.
In your controller, you may have a definition that looks like this:
$scope.MyClass = "bold-red deleted error";
Angular will evaluate the expression MyClass and find the $scope definition. It will apply the three classes "bold-
red", "deleted", and "error" to the <span> element.
Specifying classes this way lets you easily change the class definitions in your controller. For example, you may
need to change the class based on other user interactions or new data that is loaded from the server. Also, if you
have a lot of expressions to evaluate, you can do so in a function that defines the final list of classes in a $scope
variable. This can be easier than trying to squeeze many evaluations into the ng-class attribute in your HTML
template.
2. Object
This is the most commonly-used way of defining classes using ng-class because it easily lets you specify
evaluations that determine which class to use.
Specify an object containing key-value pairs. The key is the class name that will be applied if the value (a conditional)
evaluates as true.
<style>
 .red { color: red; font-weight: bold; }
 .blue { color: blue; }
 .green { color: green; }
 .highlighted { background-color: yellow; color: black; }
</style>
<span ng-class="{ red: ShowRed, blue: ShowBlue, green: ShowGreen, highlighted: IsHighlighted
}">Sample Text</span>
<div>Red: <input type="checkbox" ng-model="ShowRed"></div>
<div>Green: <input type="checkbox" ng-model="ShowGreen"></div>
<div>Blue: <input type="checkbox" ng-model="ShowBlue"></div>
<div>Highlight: <input type="checkbox" ng-model="IsHighlighted"></div>
3. Array
An expression that evaluates to an array lets you use a combination of strings (see #1 above) and conditional
objects (#2 above).
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<style>
 .bold { font-weight: bold; }
 .strike { text-decoration: line-through; }
 .orange { color: orange; }
</style>
<p ng-class="[ UserStyle, {orange: warning} ]">Array of Both Expression Types</p>
<input ng-model="UserStyle" placeholder="Type 'bold' and/or 'strike'"><br>
<label><input type="checkbox" ng-model="warning"> warning (apply "orange" class)</label>
This creates a text input field bound to the scope variable UserStyle which lets the user type in any class name(s).
These will be dynamically applied to the <p> element as the user types. Also, the user can click on the checkbox that
is data-bound to the warning scope variable. This will also be dynamically applied to the <p> element.
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Chapter 26: ng-repeat
Variable
$index number iterator offset of the repeated element (0..length-1)
Details
$first boolean true if the repeated element is first in the iterator.
$middle boolean true if the repeated element is between the first and last in the iterator.
$last
$even
$odd
boolean true if the repeated element is last in the iterator.
boolean true if the iterator position $index is even (otherwise false).
boolean true if the iterator position $index is odd (otherwise false).
The ngRepeat directive instantiates a template once per item from a collection. The collection must be an array or
an object. Each template instance gets its own scope, where the given loop variable is set to the current collection
item, and $index is set to the item index or key.
Section 26.1: ng-repeat-start + ng-repeat-end
AngularJS 1.2 ng-repeat handle multiple elements with ng-repeat-start and ng-repeat-end:
// table items
$scope.tableItems = [
 {
 row1: 'Item 1: Row 1',
 row2: 'Item 1: Row 2'
 },
 {
 row1: 'Item 2: Row 1',
 row2: 'Item 2: Row 2'
 }
];
// template
<table>
 <th>
 <td>Items</td>
 </th>
 <tr ng-repeat-start="item in tableItems">
 <td ng-bind="item.row1"></td>
 </tr>
 <tr ng-repeat-end>
 <td ng-bind="item.row2"></td>
 </tr>
</table>
Output:
Items
Item 1: Row 1
Item 1: Row 2
Item 2: Row 1
Item 2: Row 2
Section 26.2: Iterating over object properties
<div ng-repeat="(key, value) in myObj"> ... </div>
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For example
<div ng-repeat="n in [42, 42, 43, 43]">
 {{n}}
</div>
Section 26.3: Tracking and Duplicates
ngRepeat uses $watchCollection to detect changes in the collection. When a change happens, ngRepeat then makes
the corresponding changes to the DOM:
When an item is added, a new instance of the template is added to the DOM.
When an item is removed, its template instance is removed from the DOM.
When items are reordered, their respective templates are reordered in the DOM.
Duplicates
track by for any list that may include duplicate values.
track by also speeds up list changes significantly.
If you don't use track by in this case, you get the error: [ngRepeat:dupes]
$scope.numbers = ['1','1','2','3','4'];
<ul>
 <li ng-repeat="n in numbers track by $index">
 {{n}}
 </li>
</ul>
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Chapter 27: ng-style
The 'ngStyle' directive allows you to set CSS style on an HTML element conditionally. Much like how we could use
style attribute on HTML element in non-AngularJS projects, we can use ng-style in angularjs do apply styles based
on some boolean condition.
Section 27.1: Use of ng-style
Below example changes the opacity of the image based on the "status" parameter.
<img class="img-responsive" ng-src="{{imagesrc}}"
 ng-style="{'opacity' : (status == 2) ? 1 : 0.5}">
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Chapter 28: ng-view
ng-view is one of in-build directive that angular uses as a container to switch between views. {info} ngRoute is no
longer a part of the base angular.js file, so you'll need to include the angular-route.js file after your the base angular
javascript file. We can configure a route by using the “when” function of the $routeProvider. We need to first specify
the route, then in a second parameter provide an object with a templateUrl property and a controller property.
Section 28.1: Registration navigation
1.
We injecting the module in the application
var Registration=angular.module("myApp",["ngRoute"]);
2.
now we use $routeProvider from "ngRoute"
Registration.config(function($routeProvider) {
});
3.
finally we integrating the route, we define "/add" routing to the application in case application get "/add" it
divert to regi.htm
Registration.config(function($routeProvider) {
 $routeProvider
 .when("/add", {
 templateUrl : "regi.htm"
 })
});
Section 28.2: ng-view
ng-view is a directive used with $route to render a partial view in the main page layout. Here in this example,
Index.html is our main file and when user lands on "/" route the templateURL home.html will be rendered in
Index.html where ng-view is mentioned.
angular.module('ngApp', ['ngRoute'])
.config(function($routeProvider){
 $routeProvider.when("/",
 {
 templateUrl: "home.html",
 controller: "homeCtrl"
 }
 );
});
angular.module('ngApp').controller('homeCtrl',['$scope', function($scope) {
 $scope.welcome= "Welcome to stackoverflow!";
}]);
//Index.html
<body ng-app="ngApp">
 <div ng-view></div>
</body>
//Home Template URL or home.html
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<div><h2>{{welcome}}</h2></div>
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Chapter 29: AngularJS bindings options
(`=`, `@`, `&` etc.)
Section 29.1: Bind optional attribute
bindings: {
 mandatory: '='
 optional: '=?',
 foo: '=?bar'
}
Optional attributes should be marked with question mark: =? or =?bar. It is protection for ($compile:nonassign)
exception.
Section 29.2: @ one-way binding, attribute binding
Pass in a literal value (not an object), such as a string or number.
Child scope gets his own value, if it updates the value, parent scope has his own old value (child scope can't modify
the parens scope value). When parent scope value is changed, child scope value will be changed as well. All
interpolations appears every time on digest call, not only on directive creation.
<one-way text="Simple text." <!-- 'Simple text.' -->
 simple-value="123" <!-- '123' Note, is actually a string object. -->
 interpolated-value="{{parentScopeValue}}" <!-- Some value from parent scope. You can't
change parent scope value, only child scope value. Note, is actually a string object. -->
 interpolated-function-value="{{parentScopeFunction()}}" <!-- Executes parent scope
function and takes a value. -->
<!-- Unexpected usage. -->
 object-item="{{objectItem}}" <!-- Converts object|date to string. Result might be:
'{"a":5,"b":"text"}'. -->
 function-item="{{parentScopeFunction}}"> <!-- Will be an empty string. -->
</one-way>
Section 29.3: = two-way binding
Passing in a value by reference, you want to share the value between both scopes and manipulate them from both
scopes. You should not use {{...}} for interpolation.
<two-way text="'Simple text.'" <!-- 'Simple text.' -->
 simple-value="123" <!-- 123 Note, is actually a number now. -->
 interpolated-value="parentScopeValue" <!-- Some value from parent scope. You may change it
in one scope and have updated value in another. -->
 object-item="objectItem" <!-- Some object from parent scope. You may change object
properties in one scope and have updated properties in another. -->
<!-- Unexpected usage. -->
 interpolated-function-value="parentScopeFunction()" <!-- Will raise an error. -->
 function-item="incrementInterpolated"> <!-- Pass the function by reference and you may use
it in child scope. -->
</two-way>
Passing function by reference is a bad idea: to allow scope to change the definition of a function, and two
unnecessary watcher will be created, you need to minimize watchers count.
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Section 29.4: & function binding, expression binding
Pass a method into a directive. It provides a way to execute an expression in the context of the parent scope.
Method will be executed in the scope of the parent, you may pass some parameters from the child scope there.
You should not use {{...}} for interpolation. When you use & in a directive, it generates a function that returns the
value of the expression evaluated against the parent scope (not the same as = where you just pass a reference).
<expression-binding interpolated-function-value="incrementInterpolated(param)" <!--
interpolatedFunctionValue({param: 'Hey'}) will call passed function with an argument. -->
 function-item="incrementInterpolated" <!-- functionItem({param: 'Hey'})() will
call passed function, but with no possibility set up a parameter. -->
 text="'Simple text.'" <!-- text() == 'Simple text.'-->
 simple-value="123" <!-- simpleValue() == 123 -->
 interpolated-value="parentScopeValue" <!-- interpolatedValue() == Some value
from parent scope. -->
 object-item="objectItem"> <!-- objectItem() == Object item from parent scope. -
->
</expression-binding>
All parameters will be wrapped into functions.
Section 29.5: Available binding through a simple sample
angular.component("SampleComponent", {
 bindings: {
 title: '@',
 movies: '<',
 reservation: "=",
 processReservation: "&"
 }
});
Here we have all binding elements.
@ indicates that we need a very basic binding, from the parent scope to the children scope, without any watcher,
in any way. Every update in the parent scope would stay in the parent scope, and any update on the child scope
would not be communicated to the parent scope.
< indicates a one way binding. Updates in the parent scope would be propagated to the children scope, but any
update in the children scope would not be applied to the parent scope.
= is already known as a two-way binding. Every update on the parent scope would be applied on the children ones,
and every child update would be applied to the parent scope.
& is now used for an output binding. According to the component documentation, it should be used to reference
the parent scope method. Instead of manipulating the children scope, just call the parent method with the updated
data!
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Chapter 30: Providers
Section 30.1: Provider
Provider is available both in configuration and run phases.
The Provider recipe is syntactically defined as a custom type that implements a $get method.
You should use the Provider recipe only when you want to expose an API for application-wide
configuration that must be made before the application starts. This is usually interesting only for reusable
services whose behavior might need to vary slightly between applications.
angular.module('app',[])
 .provider('endpointProvider', function() {
 var uri = 'n/a';
this.set = function(value) {
 uri = value;
 };
this.$get = function() {
 return {
 get: function() {
 return uri;
 }
 };
 };
 })
 .config(function(endpointProviderProvider) {
 endpointProviderProvider.set('http://some.rest.endpoint');
 })
.controller('MainCtrl', function(endpointProvider) {
 var vm = this;
 vm.endpoint = endpointProvider.get();
 });
<body ng-controller="MainCtrl as vm">
 <div>endpoint = {{::vm.endpoint }}</div>
</body>
endpoint = http://some.rest.endpoint
Without config phase result would be
endpoint = n/a
Section 30.2: Factory
Factory is available in run phase.
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The Factory recipe constructs a new service using a function with zero or more arguments (these are
dependencies on other services). The return value of this function is the service instance created by this
recipe.
Factory can create a service of any type, whether it be a primitive, object literal, function, or even an
instance of a custom type.
angular.module('app',[])
 .factory('endpointFactory', function() {
 return {
 get: function() {
 return 'http://some.rest.endpoint';
 }
 };
 })
 .controller('MainCtrl', function(endpointFactory) {
 var vm = this;
 vm.endpoint = endpointFactory.get();
 });
<body ng-controller="MainCtrl as vm">
 <div>endpoint = {{::vm.endpoint }}</div>
</body>
endpoint = http://some.rest.endpoint
Section 30.3: Constant
Constant is available both in configuration and run phases.
angular.module('app',[])
 .constant('endpoint', 'http://some.rest.endpoint') // define
 .config(function(endpoint) {
 // do something with endpoint
 // available in both config- and run phases
 })
 .controller('MainCtrl', function(endpoint) { // inject
 var vm = this;
 vm.endpoint = endpoint; // usage
 });
<body ng-controller="MainCtrl as vm">
 <div>endpoint = {{ ::vm.endpoint }}</div>
</body>
endpoint = http://some.rest.endpoint
Section 30.4: Service
Service is available in run phase.
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The Service recipe produces a service just like the Value or Factory recipes, but it does so by invoking a
constructor with the new operator. The constructor can take zero or more arguments, which represent
dependencies needed by the instance of this type.
angular.module('app',[])
 .service('endpointService', function() {
 this.get = function() {
 return 'http://some.rest.endpoint';
 };
 })
 .controller('MainCtrl', function(endpointService) {
 var vm = this;
 vm.endpoint = endpointService.get();
 });
<body ng-controller="MainCtrl as vm">
 <div>endpoint = {{::vm.endpoint }}</div>
</body>
endpoint = http://some.rest.endpoint
Section 30.5: Value
Value is available both in configuration and run phases.
angular.module('app',[])
 .value('endpoint', 'http://some.rest.endpoint') // define
 .run(function(endpoint) {
 // do something with endpoint
 // only available in run phase
 })
 .controller('MainCtrl', function(endpoint) { // inject
 var vm = this;
 vm.endpoint = endpoint; // usage
 });
<body ng-controller="MainCtrl as vm">
 <div>endpoint = {{ ::vm.endpoint }}</div>
</body>
endpoint = http://some.rest.endpoint
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Chapter 31: Decorators
Section 31.1: Decorate service, factory
Below is example of service decorator, overriding null date returned by service.
angular.module('app', [])
 .config(function($provide) {
 $provide.decorator('myService', function($delegate) {
 $delegate.getDate = function() { // override with actual date object
 return new Date();
 };
 return $delegate;
 });
 })
 .service('myService', function() {
 this.getDate = function() {
 return null; // w/o decoration we'll be returning null
 };
 })
 .controller('myController', function(myService) {
 var vm = this;
 vm.date = myService.getDate();
 });
<body ng-controller="myController as vm">
 <div ng-bind="vm.date | date:'fullDate'"></div>
</body>
Section 31.2: Decorate directive
Directives can be decorated just like services and we can modify or replace any of it's functionality. Note that
directive itself is accessed at position 0 in $delegate array and name parameter in decorator must include
Directive suffix (case sensitive).
So, if directive is called myDate, it can be accessed using myDateDirective using $delegate[0].
Below is simple example where directive shows current time. We'll decorate it to update current time in one second
intervals. Without decoration it will always show same time.
<body>
 <my-date></my-date>
</body>
angular.module('app', [])
 .config(function($provide) {
 $provide.decorator('myDateDirective', function($delegate, $interval) {
 var directive = $delegate[0]; // access directive
directive.compile = function() { // modify compile fn
 return function(scope) {
 directive.link.apply(this, arguments);
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$interval(function() {
 scope.date = new Date(); // update date every second
 }, 1000);
 };
 };
return $delegate;
 });
 })
 .directive('myDate', function() {
 return {
 restrict: 'E',
 template: '<span>Current time is {{ date | date:\'MM:ss\' }}</span>',
 link: function(scope) {
 scope.date = new Date(); // get current date
 }
 };
 });
Section 31.3: Decorate filter
When decorating filters, name parameter must include Filter suffix (case sensitive). If filter is called repeat,
decorator parameter is repeatFilter. Below we'll decorate custom filter that repeats any given string n times so
that result is reversed. You can also decorate angular's build-in filters the same way, although not recommended as
it can affect the functionality of the framework.
<body>
 <div ng-bind="'i can haz cheeseburger ' | repeat:2"></div>
</body>
angular.module('app', [])
 .config(function($provide) {
 $provide.decorator('repeatFilter', function($delegate) {
 return function reverse(input, count) {
 // reverse repeated string
 return ($delegate(input, count)).split('').reverse().join('');
 };
 });
 })
 .filter('repeat', function() {
 return function(input, count) {
 // repeat string n times
 return (input || '').repeat(count || 1);
 };
 });
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Chapter 32: Print
Section 32.1: Print Service
Service:
angular.module('core').factory('print_service', ['$rootScope', '$compile', '$http',
'$timeout','$q',
 function($rootScope, $compile, $http, $timeout,$q) {
var printHtml = function (html) {
 var deferred = $q.defer();
 var hiddenFrame = $('<iframe style="display: none"></iframe>').appendTo('body')[0];
hiddenFrame.contentWindow.printAndRemove = function() {
 hiddenFrame.contentWindow.print();
 $(hiddenFrame).remove();
 deferred.resolve();
 };
var htmlContent = "<!doctype html>"+
 "<html>"+
 '<head><link rel="stylesheet" type="text/css"
href="/style/css/print.css"/></head>'+
 '<body onload="printAndRemove();">' +
 html +
 '</body>'+
 "</html>";
var doc = hiddenFrame.contentWindow.document.open("text/html", "replace");
 doc.write(htmlContent);
 doc.close();
 return deferred.promise;
 };
var openNewWindow = function (html) {
 var newWindow = window.open("debugPrint.html");
 newWindow.addEventListener('load', function(){
 $(newWindow.document.body).html(html);
 }, false);
 };
var print = function (templateUrl, data) {
$rootScope.isBeingPrinted = true;
$http.get(templateUrl).success(function(template){
 var printScope = $rootScope.$new()
 angular.extend(printScope, data);
 var element = $compile($('<div>' + template + '</div>'))(printScope);
 var waitForRenderAndPrint = function() {
 if(printScope.$$phase || $http.pendingRequests.length) {
 $timeout(waitForRenderAndPrint, 1000);
 } else {
 // Replace printHtml with openNewWindow for debugging
 printHtml(element.html());
 printScope.$destroy();
 }
 };
 waitForRenderAndPrint();
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});
 };
var printFromScope = function (templateUrl, scope, afterPrint) {
 $rootScope.isBeingPrinted = true;
 $http.get(templateUrl).then(function(response){
 var template = response.data;
 var printScope = scope;
 var element = $compile($('<div>' + template + '</div>'))(printScope);
 var waitForRenderAndPrint = function() {
 if (printScope.$$phase || $http.pendingRequests.length) {
 $timeout(waitForRenderAndPrint);
 } else {
 // Replace printHtml with openNewWindow for debugging
 printHtml(element.html()).then(function() {
 $rootScope.isBeingPrinted = false;
 if (afterPrint) {
 afterPrint();
 }
 });
 }
 };
 waitForRenderAndPrint();
 });
 };
return {
 print : print,
 printFromScope : printFromScope
 }
 }
]);
Controller :
var template_url = '/views/print.client.view.html';
print_service.printFromScope(template_url,$scope,function(){
 // Print Completed
});
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Chapter 33: ui-router
Section 33.1: Basic Example
app.js
angular.module('myApp', ['ui.router'])
 .controller('controllerOne', function() {
 this.message = 'Hello world from Controller One!';
 })
 .controller('controllerTwo', function() {
 this.message = 'Hello world from Controller Two!';
 })
 .controller('controllerThree', function() {
 this.message = 'Hello world from Controller Three!';
 })
 .config(function($stateProvider, $urlRouterProvider) {
 $stateProvider
 .state('one', {
 url: "/one",
 templateUrl: "view-one.html",
 controller: 'controllerOne',
 controllerAs: 'ctrlOne'
 })
 .state('two', {
 url: "/two",
 templateUrl: "view-two.html",
 controller: 'controllerTwo',
 controllerAs: 'ctrlTwo'
 })
 .state('three', {
 url: "/three",
 templateUrl: "view-three.html",
 controller: 'controllerThree',
 controllerAs: 'ctrlThree'
 });
$urlRouterProvider.otherwise('/one');
 });
index.html
<div ng-app="myApp">
 <nav>
 <!-- links to switch routes -->
 <a ui-sref="one">View One</a>
 <a ui-sref="two">View Two</a>
 <a ui-sref="three">View Three</a>
 </nav>
 <!-- views will be injected here -->
 <div ui-view></div>
 <!-- templates can live in normal html files -->
 <script type="text/ng-template" id="view-one.html">
 <h1>{{ctrlOne.message}}</h1>
 </script>
<script type="text/ng-template" id="view-two.html">
 <h1>{{ctrlTwo.message}}</h1>
 </script>
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<script type="text/ng-template" id="view-three.html">
 <h1>{{ctrlThree.message}}</h1>
 </script>
</div>
Section 33.2: Multiple Views
app.js
angular.module('myApp', ['ui.router'])
 .controller('controllerOne', function() {
 this.message = 'Hello world from Controller One!';
 })
 .controller('controllerTwo', function() {
 this.message = 'Hello world from Controller Two!';
 })
 .controller('controllerThree', function() {
 this.message = 'Hello world from Controller Three!';
 })
 .controller('controllerFour', function() {
 this.message = 'Hello world from Controller Four!';
 })
 .config(function($stateProvider, $urlRouterProvider) {
 $stateProvider
 .state('one', {
 url: "/one",
 views: {
 "viewA": {
 templateUrl: "view-one.html",
 controller: 'controllerOne',
 controllerAs: 'ctrlOne'
 },
 "viewB": {
 templateUrl: "view-two.html",
 controller: 'controllerTwo',
 controllerAs: 'ctrlTwo'
 }
 }
 })
 .state('two', {
 url: "/two",
 views: {
 "viewA": {
 templateUrl: "view-three.html",
 controller: 'controllerThree',
 controllerAs: 'ctrlThree'
 },
 "viewB": {
 templateUrl: "view-four.html",
 controller: 'controllerFour',
 controllerAs: 'ctrlFour'
 }
 }
 });
$urlRouterProvider.otherwise('/one');
 });
index.html
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<div ng-app="myApp">
 <nav>
 <!-- links to switch routes -->
 <a ui-sref="one">Route One</a>
 <a ui-sref="two">Route Two</a>
 </nav>
 <!-- views will be injected here -->
 <div ui-view="viewA"></div>
 <div ui-view="viewB"></div>
 <!-- templates can live in normal html files -->
 <script type="text/ng-template" id="view-one.html">
 <h1>{{ctrlOne.message}}</h1>
 </script>
<script type="text/ng-template" id="view-two.html">
 <h1>{{ctrlTwo.message}}</h1>
 </script>
<script type="text/ng-template" id="view-three.html">
 <h1>{{ctrlThree.message}}</h1>
 </script>
<script type="text/ng-template" id="view-four.html">
 <h1>{{ctrlFour.message}}</h1>
 </script>
</div>
Section 33.3: Using resolve functions to load data
app.js
angular.module('myApp', ['ui.router'])
 .service('User', ['$http', function User ($http) {
 this.getProfile = function (id) {
 return $http.get(...) // method to load data from API
 };
 }])
 .controller('profileCtrl', ['profile', function profileCtrl (profile) {
 // inject resolved data under the name of the resolve function
 // data will already be returned and processed
 this.profile = profile;
 }])
 .config(['$stateProvider', '$urlRouterProvider', function ($stateProvider, $urlRouterProvider) {
 $stateProvider
 .state('profile', {
 url: "/profile/:userId",
 templateUrl: "profile.html",
 controller: 'profileCtrl',
 controllerAs: 'vm',
 resolve: {
 profile: ['$stateParams', 'User', function ($stateParams, User) {
 // $stateParams will contain any parameter defined in your url
 return User.getProfile($stateParams.userId)
 // .then is only necessary if you need to process returned data
 .then(function (data) {
 return doSomeProcessing(data);
 });
 }]
 }
 }]);
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$urlRouterProvider.otherwise('/');
 });
profile.html
<ul>
 <li>Name: {{vm.profile.name}}</li>
 <li>Age: {{vm.profile.age}}</li>
 <li>Sex: {{vm.profile.sex}}</li>
</ul>
View UI-Router Wiki entry on resolves here.
Resolve functions must be resolved before the $stateChangeSuccess event is fired, which means that the UI will
not load until all resolve functions on the state have finished. This is a great way to ensure that data will be
available to your controller and UI. However, you can see that a resolve function should be fast in order to avoid
hanging the UI.
Section 33.4: Nested Views / States
app.js
var app = angular.module('myApp',['ui.router']);
app.config(function($stateProvider,$urlRouterProvider) {
$stateProvider
.state('home', {
 url: '/home',
 templateUrl: 'home.html',
 controller: function($scope){
 $scope.text = 'This is the Home'
 }
 })
.state('home.nested1',{
 url: '/nested1',
 templateUrl:'nested1.html',
 controller: function($scope){
 $scope.text1 = 'This is the nested view 1'
 }
 })
.state('home.nested2',{
 url: '/nested2',
 templateUrl:'nested2.html',
 controller: function($scope){
 $scope.fruits = ['apple','mango','oranges'];
 }
 });
$urlRouterProvider.otherwise('/home');
});
index.html
<div ui-view></div>
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<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.8/angular.min.js"></script>
 <script src="angular-ui-router.min.js"></script>
 <script src="app.js"></script>
home.html
<div>
<h1> {{text}} </h1>
<br>
 <a ui-sref="home.nested1">Show nested1</a>
 <br>
 <a ui-sref="home.nested2">Show nested2</a>
 <br>
<div ui-view></div>
</div>
nested1.html
<div>
<h1> {{text1}} </h1>
</div>
nested2.html
<div>
 <ul>
 <li ng-repeat="fruit in fruits">{{ fruit }}</li>
 </ul>
</div>
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Chapter 34: Built-in helper Functions
Section 34.1: angular.equals
The angular.equals function compares and determines if 2 objects or values are equal, angular.equals performs
a deep comparison and returns true if and only if at least 1 of the following conditions is met.
angular.equals(value1, value2)
1.
2.
3.
4.
If the objects or values pass the === comparison
If both objects or values are of the same type, and all of their properties are also equal by using
angular.equals
Both values are equal to NaN
Both values represent the same regular expression's result.
This function is helpful when you need to deep compare objects or arrays by their values or results rather than just
references.
Examples
angular.equals(1, 1) // true
angular.equals(1, 2) // false
angular.equals({}, {}) // true, note that {}==={} is false
angular.equals({a: 1}, {a: 1}) // true
angular.equals({a: 1}, {a: 2}) // false
angular.equals(NaN, NaN) // true
Section 34.2: angular.toJson
The function angular.toJson will take an object and serialize it into a JSON formatted string.
Unlike the native function JSON.stringify, This function will remove all properties beginning with $$ (as angular
usually prefixes internal properties with $$)
angular.toJson(object)
As data needs to be serialized before passing through a network, this function is useful to turn any data you wish to
transmit into JSON.
This function is also useful for debugging as it works similarly to a .toString method would act.
Examples:
angular.toJson({name: "barf", occupation: "mog", $$somebizzareproperty: 42})
// "{"name":"barf","occupation":"mog"}"
angular.toJson(42)
// "42"
angular.toJson([1, "2", 3, "4"])
// "[1,"2",3,"4"]"
var fn = function(value) {return value}
angular.toJson(fn)
// undefined, functions have no representation in JSON
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Section 34.3: angular.copy
The angular.copy function takes an object, array or a value and creates a deep copy of it.
angular.copy()
Example:
Objects:
let obj = {name: "vespa", occupation: "princess"};
let cpy = angular.copy(obj);
cpy.name = "yogurt"
// obj = {name: "vespa", occupation: "princess"}
// cpy = {name: "yogurt", occupation: "princess"}
Arrays:
var w = [a, [b, [c, [d]]]];
var q = angular.copy(w);
// q = [a, [b, [c, [d]]]]
At the above example angular.equals(w, q) will evaluate to true because .equals tests equality by value.
however w === q will evaluate to false because strict comparison between objects and arrays is done by reference.
Section 34.4: angular.isString
The function angular.isString returns true if the object or value given to it is of the type string
angular.isString(value1)
Examples
angular.isString("hello") // true
angular.isString([1, 2]) // false
angular.isString(42) // false
This is the equivalent of performing
typeof someValue === "string"
Section 34.5: angular.isArray
The angular.isArray function returns true if and only if the object or value passed to it is of the type Array.
angular.isArray(value)
Examples
angular.isArray([]) // true
angular.isArray([2, 3]) // true
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angular.isArray({}) // false
angular.isArray(17) // false
It is the equivalent of
Array.isArray(someValue)
Section 34.6: angular.merge
The function angular.merge takes all the enumerable properties from the source object to deeply extend the
destination object.
The function returns a reference to the now extended destination object
angular.merge(destination, source)
Examples
angular.merge({}, {}) // {}
angular.merge({name: "king roland"}, {password: "12345"})
// {name: "king roland", password: "12345"}
angular.merge({a: 1}, [4, 5, 6]) // {0: 4, 1: 5, 2: 6, a: 1}
angular.merge({a: 1}, {b: {c: {d: 2}}}) // {"a":1,"b":{"c":{"d":2}}}
Section 34.7: angular.isDefined and angular.isUndefined
The function angular.isDefined tests a value if it is defined
angular.isDefined(someValue)
This is the equivalent of performing
value !== undefined; // will evaluate to true is value is defined
Examples
angular.isDefined(42) // true
angular.isDefined([1, 2]) // true
angular.isDefined(undefined) // false
angular.isDefined(null) // true
The function angular.isUndefined tests if a value is undefined (it is effectively the opposite of angular.isDefined)
angular.isUndefined(someValue)
This is the equivalent of performing
value === undefined; // will evaluate to true is value is undefined
Or just
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!angular.isDefined(value)
Examples
angular.isUndefined(42) // false
angular.isUndefined(undefined) // true
Section 34.8: angular.isDate
The angular.isDate function returns true if and only if the object passed to it is of the type Date.
angular.isDate(value)
Examples
angular.isDate("lone star") // false
angular.isDate(new Date()) // true
Section 34.9: angular.noop
The angular.noop is a function that performs no operations, you pass angular.noop when you need to provide a
function argument that will do nothing.
angular.noop()
A common use for angular.noop can be to provide an empty callback to a function that will otherwise throw an
error when something else than a function is passed to it.
Example:
$scope.onSomeChange = function(model, callback) {
 updateTheModel(model);
 if (angular.isFunction(callback)) {
 callback();
 } else {
 throw new Error("error: callback is not a function!");
 }
};
$scope.onSomeChange(42, function() {console.log("hello callback")});
// will update the model and print 'hello callback'
$scope.onSomeChange(42, angular.noop);
// will update the model
Additional examples:
angular.noop() // undefined
angular.isFunction(angular.noop) // true
Section 34.10: angular.isElement
The angular.isElement returns true if the argument passed to it is a DOM Element or a jQuery wrapped Element.
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angular.isElement(elem)
This function is useful to type check if a passed argument is an element before being processed as such.
Examples:
angular.isElement(document.querySelector("body"))
// true
angular.isElement(document.querySelector("#some_id"))
// false if "some_id" is not using as an id inside the selected DOM
angular.isElement("<div></div>")
// false
Section 34.11: angular.isFunction
The function angular.isFunction determines and returns true if and only if the value passed to is a reference to a
function.
The function returns a reference to the now extended destination object
angular.isFunction(fn)
Examples
var onClick = function(e) {return e};
angular.isFunction(onClick); // true
var someArray = ["pizza", "the", "hut"];
angular.isFunction(someArray ); // false
Section 34.12: angular.identity
The angular.identity function returns the first argument passed to it.
angular.identity(argument)
This function is useful for functional programming, you can provide this function as a default in case an expected
function was not passed.
Examples:
angular.identity(42) // 42
var mutate = function(fn, num) {
 return angular.isFunction(fn) ? fn(num) : angular.identity(num)
}
mutate(function(value) {return value-7}, 42) // 35
mutate(null, 42) // 42
mutate("mount. rushmore", 42) // 42
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Section 34.13: angular.forEach
The angular.forEach accepts an object and an iterator function. It then runs the iterator function over each
enumerable property/value of the object. This function also works on arrays.
Like the JS version of Array.prototype.forEach The function does not iterate over inherited properties (prototype
properties), however the function will not attempt to process a null or an undefined value and will just return it.
angular.forEach(object, function(value, key) { // function});
Examples:
angular.forEach({"a": 12, "b": 34}, (value, key) => console.log("key: " + key + ", value: " +
value))
// key: a, value: 12
// key: b, value: 34
angular.forEach([2, 4, 6, 8, 10], (value, key) => console.log(key))
// will print the array indices: 1, 2, 3, 4, 5
angular.forEach([2, 4, 6, 8, 10], (value, key) => console.log(value))
// will print the array values: 2, 4, 6, 7, 10
angular.forEach(undefined, (value, key) => console.log("key: " + key + ", value: " + value))
// undefined
Section 34.14: angular.isNumber
The angular.isNumber function returns true if and only if the object or value passed to it is of the type Number, this
includes +Infinity, -Infinity and NaN
angular.isNumber(value)
This function will not cause a type coercion such as
"23" == 23 // true
Examples
angular.isNumber("23") // false
angular.isNumber(23) // true
angular.isNumber(NaN) // true
angular.isNumber(Infinity) // true
This function will not cause a type coercion such as
"23" == 23 // true
Section 34.15: angular.isObject
The angular.isObject return true if and only if the argument passed to it is an object, this function will also return
true for an Array and will return false for null even though typeof null is object .
angular.isObject(value)
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This function is useful for type checking when you need a defined object to process.
Examples:
angular.isObject({name: "skroob", job: "president"})
// true
angular.isObject(null)
// false
angular.isObject([null])
// true
angular.isObject(new Date())
// true
angular.isObject(undefined)
// false
Section 34.16: angular.fromJson
The function angular.fromJson will deserialize a valid JSON string and return an Object or an Array.
angular.fromJson(string|object)
Note that this function is not limited to only strings, it will output a representation of any object passed to it.
Examples:
angular.fromJson("{\"yogurt\": \"strawberries\"}")
// Object {yogurt: "strawberries"}
angular.fromJson('{jam: "raspberries"}')
// will throw an exception as the string is not a valid JSON
angular.fromJson(this)
// Window {external: Object, chrome: Object, _gaq: Y, angular: Object, ng339: 3…}
angular.fromJson([1, 2])
// [1, 2]
typeof angular.fromJson(new Date())
// "object"
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Chapter 35: digest loop walkthrough
Section 35.1: $digest and $watch
Implementing two-way-data-binding, to achieve the result from the previous example, could be done with two core
functions:
$digest is called after a user interaction (binding DOM=>variable)
$watch sets a callback to be called after variable changes (binding variable=>DOM)
note: this is example is a demonstration, not the actual angular code
<input id="input"/>
<span id="span"></span>
The two functions we need:
var $watches = [];
function $digest(){
 $watches.forEach(function($w){
 var val = $w.val();
 if($w.prevVal !== val){
 $w.callback(val, $w.prevVal);
 $w.prevVal = val;
 }
 })
}
function $watch(val, callback){
 $watches.push({val:val, callback:callback, prevVal: val() })
}
Now we could now use these functions to hook up a variable to the DOM (angular comes with built-in directives
which will do this for you):
var realVar;
//this is usually done by ng-model directive
input1.addEventListener('keyup',function(e){
 realVar=e.target.value;
 $digest()
}, true);
//this is usually done with {{expressions}} or ng-bind directive
$watch(function(){return realVar},function(val){
 span1.innerHTML = val;
});
Off-course, the real implementations are more complex, and support parameters such as which element to bind
to, and what variable to use
A running example could be found here: https://jsfiddle.net/azofxd4j/
Section 35.2: the $scope tree
The previous example is good enough when we need to bind a single html element, to a single variable.
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In reality - we need to bind many elements to many variables:
<span ng-repeat="number in [1,2,3,4,5]">{{number}}</span>
This ng-repeat binds 5 elements to 5 variables called number, with a different value for each of them!
The way angular achieves this behavior is using a separate context for each element which needs separate
variables. This context is called a scope.
Each scope contains properties, which are the variables bound to the DOM, and the $digest and $watch functions
are implemented as methods of the scope.
The DOM is a tree, and variables need to be used in different levels of the tree:
<div>
 <input ng-model="person.name" />
 <span ng-repeat="number in [1,2,3,4,5]">{{number}} {{person.name}}</span>
</div>
But as we saw, the context(or scope) of variables inside ng-repeat is different to the context above it. To solve this -
angular implements scopes as a tree.
Each scope has an array of children, and calling its $digest method will run all of its children's $digest method.
This way - after changing the input - $digest is called for the div's scope, which then runs the $digest for its 5
children - which will update its content.
A simple implementation for a scope, could look like this:
function $scope(){
 this.$children = [];
 this.$watches = [];
}
$scope.prototype.$digest = function(){
 this.$watches.forEach(function($w){
 var val = $w.val();
 if($w.prevVal !== val){
 $w.callback(val, $w.prevVal);
 $w.prevVal = val;
 }
 });
 this.$children.forEach(function(c){
 c.$digest();
 });
}
$scope.prototype.$watch = function(val, callback){
 this.$watches.push({val:val, callback:callback, prevVal: val() })
}
note: this is example is a demonstration, not the actual angular code
Section 35.3: two way data binding
Angular has some magic under its hood. it enables binding DOM to real js variables.
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Angular uses a loop, named the "digest loop", which is called after any change of a variable - calling callbacks which
update the DOM.
For example, the ng-model directive attaches a keyup eventListener to this input:
<input ng-model="variable" />
Every time the keyup event fires, the digest loop starts.
At some point, the digest loop iterates over a callback which updates the contents of this span:
<span>{{variable}}</span>
The basic life-cycle of this example, summarizes (very Schematically) how angular works::
1.
Angular scans html
ng-model directive creates a keyup listener on input
expression inside span adds a callback to digest cycle
2.
User interacts with input
keyup listener starts digest cycle
digest cycle calles the callback
Callback updates span's contents
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Chapter 36: Angular $scopes
Section 36.1: A function available in the entire app
Be careful, this approach might be considered as a bad design for angular apps, since it requires programmers to
remember both where functions are placed in the scope tree, and to be aware of scope inheritance. In many cases
it would be preferred to inject a service (Angular practice - using scope inheritance vs injection.
This example only show how scope inheritance could be used for our needs, and the how you could take advantage
of it, and not the best practices of designing an entire app.
In some cases, we could take advantage of scope inheritance, and set a function as a property of the rootScope.
This way - all of the scopes in the app (except for isolated scopes) will inherit this function, and it could be called
from anywhere in the app.
angular.module('app', [])
.run(['$rootScope', function($rootScope){
 var messages = []
 $rootScope.addMessage = function(msg){
 messages.push(msg);
 }
}]);
<div ng-app="app">
 <a ng-click="addMessage('hello world!')">it could be accsessed from here</a>
 <div ng-include="inner.html"></div>
</div>
inner.html:
<div>
 <button ng-click="addMessage('page')">and from here to!</button>
</div>
Section 36.2: Avoid inheriting primitive values
In javascript, assigning a non-primitive value (Such as Object, Array, Function, and many more), keeps a reference
(an address in the memory) to the assigned value.
Assigning a primitive value (String, Number, Boolean, or Symbol) to two different variables, and changing one, won't
change both:
var x = 5;
var y = x;
y = 6;
console.log(y === x, x, y); //false, 5, 6
But with a non-primitive value, since both variables are simply keeping references to the same object, changing one
variable will change the other:
var x = { name : 'John Doe' };
var y = x;
y.name = 'Jhon';
console.log(x.name === y.name, x.name, y.name); //true, John, John
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In angular, when a scope is created, it is assigned all of its parent's properties However, changing properties
afterwards will only affect the parent scope if it is a non-primitive value:
angular.module('app', [])
.controller('myController', ['$scope', function($scope){
 $scope.person = { name: 'John Doe' }; //non-primitive
 $scope.name = 'Jhon Doe'; //primitive
}])
.controller('myController1', ['$scope', function($scope){}]);
<div ng-app="app" ng-controller="myController">
 binding to input works: {{person.name}}<br/>
 binding to input does not work: {{name}}<br/>
 <div ng-controller="myController1">
 <input ng-model="person.name" />
 <input ng-model="name" />
 </div>
</div>
Remember: in Angular scopes can be created in many ways (such as built-in or custom directives, or the
$scope.$new() function), and keeping track of the scope tree is probably impossible.
Using only non-primitive values as scope properties will keep you on the safe side (unless you need a property to
not inherit, or other cases where you are aware of scope inheritance).
Section 36.3: Basic Example of $scope inheritance
angular.module('app', [])
.controller('myController', ['$scope', function($scope){
 $scope.person = { name: 'John Doe' };
}]);
<div ng-app="app" ng-conroller="myController">
 <input ng-model="person.name" />
 <div ng-repeat="number in [0,1,2,3]">
 {{person.name}} {{number}}
 </div>
</div>
In this example, the ng-repeat directive creates a new scope for each of its newly created children.
These created scopes are children of their parent scope (in this case the scope created by myController), and
therfore, they inherit all of its proporties, such as person.
Section 36.4: How can you limit the scope on a directive and
why would you do this?
Scope is used as the "glue" that we use to communicate between the parent controller, the directive, and the
directive template. Whenever the AngularJS application is bootstrapped, a rootScope object is created. Each scope
created by controllers, directives and services are prototypically inherited from rootScope.
Yes, we can limit the scope on a directive . We can do so by creating an isolated scope for directive.
There are 3 types of directive scopes:
1.
Scope : False ( Directive uses its parent scope )
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2.
3.
Scope : True ( Directive gets a new scope )
Scope : { } ( Directive gets a new isolated scope )
Directives with the new isolated scope: When we create a new isolated scope then it will not be inherited from
the parent scope. This new scope is called Isolated scope because it is completely detached from its parent scope.
Why? should we use isolated scope: We should use isolated scope when we want to create a custom directive
because it will make sure that our directive is generic, and placed anywhere inside the application. Parent scope is
not going to interfere with the directive scope.
Example of isolated scope:
var app = angular.module("test",[]);
app.controller("Ctrl1",function($scope){
 $scope.name = "Prateek";
 $scope.reverseName = function(){
 $scope.name = $scope.name.split('').reverse().join('');
 };
});
app.directive("myDirective", function(){
 return {
 restrict: "EA",
 scope: {},
 template: "<div>Your name is : {{name}}</div>"+
 "Change your name : <input type='text' ng-model='name'/>"
 };
});
There’re 3 types of prefixes AngularJS provides for isolated scope these are :
1.
2.
3.
"@" ( Text binding / one-way binding )
"=" ( Direct model binding / two-way binding )
"&" ( Behaviour binding / Method binding )
All these prefixes receives data from the attributes of the directive element like :
<div my-directive
 class="directive"
 name="{{name}}"
 reverse="reverseName()"
 color="color" >
</div>
Section 36.5: Using $scope functions
While declaring a function in the $rootscope has it's advantages, we can also declare a $scope function any part of
the code that is injected by the $scope service. Controller, for instance.
Controller
myApp.controller('myController', ['$scope', function($scope){
 $scope.myFunction = function () {
 alert("You are in myFunction!");
 };
}]);
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Now you can call your function from the controller using:
$scope.myfunction();
Or via HTML that is under that specific controller:
<div ng-controller="myController">
 <button ng-click="myFunction()"> Click me! </button>
</div>
Directive
An angular directive is another place you can use your scope:
myApp.directive('triggerFunction', function() {
 return {
 scope: {
 triggerFunction: '&'
 },
 link: function(scope, element) {
 element.bind('mouseover', function() {
 scope.triggerFunction();
 });
 }
 };
});
And in your HTML code under the same controller:
<div ng-controller="myController">
 <button trigger-function="myFunction()"> Hover over me! </button>
</div>
Of course, you can use ngMouseover for the same thing, but what's special about directives is that you can
customize them the way you want. And now you know how to use your $scope functions inside them, be creative!
Section 36.6: Creating custom $scope events
Like normal HTML elements, it is possible for $scopes to have their own events. $scope events can be subscribed to
using the following manner:
$scope.$on('my-event', function(event, args) {
 console.log(args); // { custom: 'data' }
});
If you need unregister an event listener, the $on function will return an unbinding function. To continue with the
above example:
var unregisterMyEvent = $scope.$on('my-event', function(event, args) {
 console.log(args); // { custom: 'data' }
 unregisterMyEvent();
});
There are two ways of triggering your own custom $scope event $broadcast and $emit. To notify the parent(s) of a
scope of a specific event, use $emit
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$scope.$emit('my-event', { custom: 'data' });
The above example will trigger any event listeners for my-event on the parent scope and will continue up the scope
tree to $rootScope unless a listener calls stopPropagation on the event. Only events triggered with $emit may call
stopPropagation
The reverse of $emit is $broadcast, which will trigger any event listeners on all child scopes in the scope tree that
are children of the scope that called $broadcast.
$scope.$broadcast('my-event', { custom: 'data' });
Events triggered with $broadcast cannot be canceled.
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Chapter 37: Using AngularJS with
TypeScript
Section 37.1: Using Bundling / Minification
The way the $scope is injected in the controller's constructor functions is a way to demonstrate and use the basic
option of angular dependency injection but is not production ready as it cannot be minified. Thats because the
minification system changes the variable names and anguar's dependency injection uses the parameter names to
know what has to be injected. So for an example the ExampleController's constructor function is minified to the
following code.
function n(n){this.setUpWatches(n)
and $scope is changed to n!
to overcome this we can add an $inject array(string[]). So that angular's DI knows what to inject at what position
is the controllers constructor function.
So the above typescript changes to
module App.Controllers {
 class Address {
 line1: string;
 line2: string;
 city: string;
 state: string;
 }
 export class SampleController {
 firstName: string;
 lastName: string;
 age: number;
 address: Address;
 setUpWatches($scope: ng.IScope): void {
 $scope.$watch(() => this.firstName, (n, o) => {
 //n is string and so is o
 });
 };
 static $inject : string[] = ['$scope'];
 constructor($scope: ng.IScope) {
 this.setUpWatches($scope);
 }
 }
}
Section 37.2: Angular Controllers in Typescript
As defined in the AngularJS Documentation
When a Controller is attached to the DOM via the ng-controller directive, Angular will instantiate a new
Controller object, using the specified Controller's constructor function. A new child scope will be created
and made available as an injectable parameter to the Controller's constructor function as $scope.
Controllers can be very easily made using the typescript classes.
module App.Controllers {
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class Address {
 line1: string;
 line2: string;
 city: string;
 state: string;
 }
 export class SampleController {
 firstName: string;
 lastName: string;
 age: number;
 address: Address;
 setUpWatches($scope: ng.IScope): void {
 $scope.$watch(() => this.firstName, (n, o) => {
 //n is string and so is o
 });
 };
 constructor($scope: ng.IScope) {
 this.setUpWatches($scope);
 }
 }
}
The Resulting Javascript is
var App;
(function (App) {
 var Controllers;
 (function (Controllers) {
 var Address = (function () {
 function Address() {
 }
 return Address;
 }());
 var SampleController = (function () {
 function SampleController($scope) {
 this.setUpWatches($scope);
 }
 SampleController.prototype.setUpWatches = function ($scope) {
 var _this = this;
 $scope.$watch(function () { return _this.firstName; }, function (n, o) {
 //n is string and so is o
 });
 };
 ;
 return SampleController;
 }());
 Controllers.SampleController = SampleController;
 })(Controllers = App.Controllers || (App.Controllers = {}));
})(App || (App = {}));
//# sourceMappingURL=ExampleController.js.map
After making the controller class let the angular js module about the controller can be done simple by using the
class
app
 .module('app')
 .controller('exampleController', App.Controller.SampleController)
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Section 37.3: Using the Controller with ControllerAs Syntax
The Controller we have made can be instantiated and used using controller as Syntax. That's because we have
put variable directly on the controller class and not on the $scope.
Using controller as someName is to separate the controller from $scope itself.So, there is no need of injecting
$scope as the dependency in the controller.
Traditional way :
// we are using $scope object.
app.controller('MyCtrl', function ($scope) {
 $scope.name = 'John';
});
<div ng-controller="MyCtrl">
 {{name}}
</div>
Now, with controller as Syntax :
// we are using the "this" Object instead of "$scope"
app.controller('MyCtrl', function() {
 this.name = 'John';
});
<div ng-controller="MyCtrl as info">
 {{info.name}}
</div>
If you instantiate a "class" in JavaScript, you might do this :
var jsClass = function () {
 this.name = 'John';
}
var jsObj = new jsClass();
So, now we can use jsObj instance to access any method or property of jsClass.
In angular, we do same type of thing.we use controller as syntax for instantiation.
Section 37.4: Why ControllerAs Syntax?
Controller Function
Controller function is nothing but just a JavaScript constructor function. Hence, when a view loads the function
context(this) is set to the controller object.
Case 1 :
this.constFunction = function() { ... }
It is created in the controller object, not on $scope. views can not access the functions defined on controller
object.
Example :
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<a href="#123" ng-click="constFunction()"></a> // It will not work
Case 2 :
$scope.scopeFunction = function() { ... }
It is created in the $scope object, not on controller object. views can only access the functions defined on
$scope object.
Example :
<a href="#123" ng-click="scopeFunction()"></a> // It will work
Why ControllerAs ?
ControllerAs syntax makes it much clearer where objects are being manipulated.Having oneCtrl.name and
anotherCtrl.name makes it much easier to identify that you have an name assigned by multiple different
controllers for different purposes but if both used same $scope.name and having two different HTML
elements on a page which both are bound to {{name}} then it is difficult to identify which one is from which
controller.
Hiding the $scope and exposing the members from the controller to the view via an intermediary object.
By setting this.*, we can expose just what we want to expose from the controller to the view.
<div ng-controller="FirstCtrl">
 {{ name }}
 <div ng-controller="SecondCtrl">
 {{ name }}
 <div ng-controller="ThirdCtrl">
 {{ name }}
 </div>
 </div>
 </div>
Here, in above case {{ name }} will be very confusing to use and We also don't know which one related to which
controller.
<div ng-controller="FirstCtrl as first">
 {{ first.name }}
 <div ng-controller="SecondCtrl as second">
 {{ second.name }}
 <div ng-controller="ThirdCtrl as third">
 {{ third.name }}
 </div>
 </div>
</div>
Why $scope ?
Use $scope when you need to access one or more methods of $scope such as $watch, $digest, $emit, $http
etc.
limit which properties and/or methods are exposed to $scope, then explicitly passing them to $scope as
needed.
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Chapter 38: $http request
Section 38.1: Timing of an $http request
The $http requests require time which varies depending on the server, some may take a few milliseconds, and
some may take up to a few seconds. Often the time required to retrieve the data from a request is critical.
Assuming the response value is an array of names, consider the following example:
Incorrect
$scope.names = [];
$http({
 method: 'GET',
 url: '/someURL'
}).then(function successCallback(response) {
 $scope.names = response.data;
 },
 function errorCallback(response) {
 alert(response.status);
 });
alert("The first name is: " + $scope.names[0]);
Accessing $scope.names[0] right below the $http request will often throw an error - this line of code executes
before the response is received from the server.
Correct
$scope.names = [];
$scope.$watch('names', function(newVal, oldVal) {
 if(!(newVal.length == 0)) {
 alert("The first name is: " + $scope.names[0]);
 }
});
$http({
 method: 'GET',
 url: '/someURL'
}).then(function successCallback(response) {
 $scope.names = response.data;
 },
 function errorCallback(response) {
 alert(response.status);
 });
Using the $watch service we access the $scope.names array only when the response is received. During
initialization, the function is called even though $scope.names was initialized before, therefore checking if the
newVal.length is different than 0 is necessary. Be aware - any changes made to $scope.names will trigger the watch
function.
Section 38.2: Using $http inside a controller
The $http service is a function which generates an HTTP request and returns a promise.
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General Usage
// Simple GET request example:
$http({
 method: 'GET',
 url: '/someUrl'
}).then(function successCallback(response) {
 // this callback will be called asynchronously
 // when the response is available
 }, function errorCallback(response) {
 // called asynchronously if an error occurs
 // or server returns response with an error status.
 });
Usage inside controller
appName.controller('controllerName',
 ['$http', function($http){
// Simple GET request example:
 $http({
 method: 'GET',
 url: '/someUrl'
 }).then(function successCallback(response) {
 // this callback will be called asynchronously
 // when the response is available
 }, function errorCallback(response) {
 // called asynchronously if an error occurs
 // or server returns response with an error status.
 });
}])
Shortcut Methods
$http service also has shortcut methods. Read about http methods here
Syntax
$http.get('/someUrl', config).then(successCallback, errorCallback);
$http.post('/someUrl', data, config).then(successCallback, errorCallback);
Shortcut Methods
$http.get
$http.head
$http.post
$http.put
$http.delete
$http.jsonp
$http.patch
Section 38.3: Using $http request in a service
HTTP requests are widely used repeatedly across every web app, so it is wise to write a method for each common
request, and then use it in multiple places throughout the app.
Create a httpRequestsService.js
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httpRequestsService.js
appName.service('httpRequestsService', function($q, $http){
return {
 // function that performs a basic get request
 getName: function(){
 // make sure $http is injected
 return $http.get("/someAPI/names")
 .then(function(response) {
 // return the result as a promise
 return response;
 }, function(response) {
 // defer the promise
 return $q.reject(response.data);
 });
 },
// add functions for other requests made by your app
 addName: function(){
 // some code...
 }
 }
})
The service above will perform a get request inside the service. This will be available to any controller where the
service has been injected.
Sample usage
appName.controller('controllerName',
 ['httpRequestsService', function(httpRequestsService){
// we injected httpRequestsService service on this controller
 // that made the getName() function available to use.
 httpRequestsService.getName()
 .then(function(response){
 // success
 }, function(error){
 // do something with the error
 })
 }])
Using this approach we can now use httpRequestsService.js anytime and in any controller.
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Chapter 39: Prepare for Production - Grunt
Section 39.1: View preloading
When the first time view is requested, normally Angular makes XHR request to get that view. For mid-size projects,
the view count can be significant and it can slow down the application responsiveness.
The good practice is to pre-load all the views at once for small and mid size projects. For larger projects it is good
to aggregate them in some meaningful bulks as well, but some other methods can be handy to split the load. To
automate this task it is handy to use Grunt or Gulp tasks.
To pre-load the views, we can use $templateCache object. That is an object, where angular stores every received
view from the server.
It is possible to use html2js module, that will convert all our views to one module - js file. Then we will need to
inject that module into our application and that's it.
To create concatenated file of all the views we can use this task
module.exports = function (grunt) {
 //set up the location of your views here
 var viewLocation = ['app/views/**.html'];
grunt.initConfig({
 pkg: require('./package.json'),
 //section that sets up the settings for concatenation of the html files into one file
 html2js: {
 options: {
 base: '',
 module: 'app.templates', //new module name
 singleModule: true,
 useStrict: true,
 htmlmin: {
 collapseBooleanAttributes: true,
 collapseWhitespace: true
 }
 },
 main: {
 src: viewLocation,
 dest: 'build/app.templates.js'
 }
 },
 //this section is watching for changes in view files, and if there was a change, it will
regenerate the production file. This task can be handy during development.
 watch: {
 views:{
 files: viewLocation,
 tasks: ['buildHTML']
 },
 }
 });
//to automatically generate one view file
 grunt.loadNpmTasks('grunt-html2js');
//to watch for changes and if the file has been changed, regenerate the file
 grunt.loadNpmTasks('grunt-contrib-watch');
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//just a task with friendly name to reference in watch
 grunt.registerTask('buildHTML', ['html2js']);
};
To use this way of concatination, you need to make 2 changes: In your index.html file you need to reference the
concatenated view file
<script src="build/app.templates.js"></script>
In the file, where you are declaring your app, you need to inject the dependency
angular.module('app', ['app.templates'])
If you are using popular routers like ui-router, there are no changes in the way, how you are referencing
templates
.state('home', {
 url: '/home',
 views: {
 "@": {
 controller: 'homeController',
 //this will be picked up from $templateCache
 templateUrl: 'app/views/home.html'
 },
 }
})
Section 39.2: Script optimisation
It is good practice to combine JS files together and minify them. For larger project there could be hundreds of JS
files and it adds unnecessary latency to load each file separately from the server.
For angular minification it is required to to have all functions annotated. That in necessary for Angular dependency
injection proper minificaiton. (During minification, function names and variables will be renamed and it will break
dependency injection if no extra actions will be taken.)
During minificaiton $scope and myService variables will be replaced by some other values. Angular dependency
injection works based on the name, as a result, these names shouldn't change
.controller('myController', function($scope, myService){
})
Angular will understand the array notation, because minification won't replace string literals.
.controller('myController', ['$scope','myService', function($scope, myService){
}])
Firstly we will concatinate all files end to end.
Secondly we will use ng-annotate module, that will prepare code for minification
Finally we will apply uglify module.
module.exports = function (grunt) { //set up the location of your scripts here for reusing it in code var scriptLocation
= ['app/scripts/*.js'];
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grunt.initConfig({
 pkg: require('./package.json'),
 //add necessary annotations for safe minification
 ngAnnotate: {
 angular: {
 src: ['staging/concatenated.js'],
 dest: 'staging/anotated.js'
 }
 },
 //combines all the files into one file
 concat: {
 js: {
 src: scriptLocation,
 dest: 'staging/concatenated.js'
 }
 },
 //final uglifying
 uglify: {
 options: {
 report: 'min',
 mangle: false,
 sourceMap:true
 },
 my_target: {
 files: {
 'build/app.min.js': ['staging/anotated.js']
 }
 }
 },
//this section is watching for changes in JS files, and if there was a change, it will
regenerate the production file. You can choose not to do it, but I like to keep concatenated version
up to date
 watch: {
 scripts: {
 files: scriptLocation,
 tasks: ['buildJS']
 }
 }
});
//module to make files less readable
 grunt.loadNpmTasks('grunt-contrib-uglify');
//mdule to concatenate files together
 grunt.loadNpmTasks('grunt-contrib-concat');
//module to make angularJS files ready for minification
 grunt.loadNpmTasks('grunt-ng-annotate');
//to watch for changes and if the file has been changed, regenerate the file
 grunt.loadNpmTasks('grunt-contrib-watch');
//task that sequentially executes all steps to prepare JS file for production
 //concatinate all JS files
 //annotate JS file (prepare for minification
 //uglify file
 grunt.registerTask('buildJS', ['concat:js', 'ngAnnotate', 'uglify']);
};
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Chapter 40: Grunt tasks
Section 40.1: Run application locally
Following example requires that node.js is installed and npm is available.
Full working code can be forked from GitHub @ https://github.com/mikkoviitala/angular-grunt-run-local
Usually one of the first things you want to do when developing new web application is to make it run locally.
Below you'll find complete example achieving just that, using grunt (javascript task runner), npm (node package
manager) and bower (yet another package manager).
Beside your actual application files you'll need to install few 3rd party dependencies using tools mentioned above. In
your project directory, preferably root, you'll need three (3) files.
package.json (dependencies managed by npm)
bower.json (dependencies managed by bower)
gruntfile.js (grunt tasks)
So your project directory looks like so:
package.json
We'll be installing grunt itself, matchdep to make our life easier allowing us to filter dependencies by name, grunt-
express used to start express web server via grunt and grunt-open to open urls/files from a grunt task.
So these packages are all about "infrastructure" and helpers we'll be building our application on.
{
 "name": "app",
 "version": "1.0.0",
 "dependencies": {},
 "devDependencies": {
 "grunt": "~0.4.1",
 "matchdep": "~0.1.2",
 "grunt-express": "~1.0.0-beta2",
 "grunt-open": "~0.2.1"
 },
 "scripts": {
 "postinstall": "bower install"
 }
}
bower.json
Bower is (or at least should be) all about front-end and we'll be using it to install angular.
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{
 "name": "app",
 "version": "1.0.0",
 "dependencies": {
 "angular": "~1.3.x"
 },
 "devDependencies": {}
}
gruntfile.js
Inside gruntfile.js we'll have the actual "running application locally" magic, which opens our application in new
browser window, running on http://localhost:9000/
'use strict';
// see http://rhumaric.com/2013/07/renewing-the-grunt-livereload-magic/
module.exports = function(grunt) {
 require('matchdep').filterDev('grunt-*').forEach(grunt.loadNpmTasks);
grunt.initConfig({
 express: {
 all: {
 options: {
 port: 9000,
 hostname: 'localhost',
 bases: [__dirname]
 }
 }
 },
open: {
 all: {
 path: 'http://localhost:<%= express.all.options.port%>'
 }
 }
 });
grunt.registerTask('app', [
 'express',
 'open',
 'express-keepalive'
 ]);
};
Usage
To get your application up & running from scratch, save above files to your project's root directory (any empty
folder will do). Then fire up console/command line and type in the following to install all required dependencies.
npm install -g grunt-cli bower
npm install
And then run your application using
grunt app
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Note that yes, you'll be needing your actual application files, too.
For almost-minimal example browse GitHub repository mentioned in beginning of this example.
There structure ain't that different. There's just index.html template, angular code in app.js and few styles in
app.css. Other files are for Git and editor configuration and some generic stuff. Give it a try!
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Chapter 41: Lazy loading
Section 41.1: Preparing your project for lazy loading
After including oclazyload.js in your index file, declare ocLazyLoad as a dependency in app.js
//Make sure you put the correct dependency! it is spelled different than the service!
angular.module('app', [
 'oc.lazyLoad',
 'ui-router'
])
Section 41.2: Usage
In order to lazily load files inject the $ocLazyLoad service into a controller or another service
.controller('someCtrl', function($ocLazyLoad) {
 $ocLazyLoad.load('path/to/file.js').then(...);
});
Angular modules will be automatically loaded into angular.
Other variation:
$ocLazyLoad.load([
 'bower_components/bootstrap/dist/js/bootstrap.js',
 'bower_components/bootstrap/dist/css/bootstrap.css',
 'partials/template1.html'
]);
For a complete list of variations visit the official documentation
Section 41.3: Usage with router
UI-Router:
.state('profile', {
 url: '/profile',
 controller: 'profileCtrl as vm'
 resolve: {
 module: function($ocLazyLoad) {
 return $ocLazyLoad.load([
 'path/to/profile/module.js',
 'path/to/profile/style.css'
 ]);
 }
 }
});
ngRoute:
.when('/profile', {
 controller: 'profileCtrl as vm'
 resolve: {
 module: function($ocLazyLoad) {
 return $ocLazyLoad.load([
 'path/to/profile/module.js',
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'path/to/profile/style.css'
 ]);
 }
 }
 });
Section 41.4: Using dependency injection
The following syntax allows you to specify dependencies in your module.js instead of explicit specification when
using the service
//lazy_module.js
angular.module('lazy', [
 'alreadyLoadedDependency1',
 'alreadyLoadedDependency2',
 ...
 [
 'path/to/lazily/loaded/dependency.js',
 'path/to/lazily/loaded/dependency.css'
 ]
]);
Note: this syntax will only work for lazily loaded modules!
Section 41.5: Using the directive
<div oc-lazy-load="['path/to/lazy/loaded/directive.js', 'path/to/lazy/loaded/directive.html']">
<!-- myDirective available here -->
<my-directive></my-directive>
</div>
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Chapter 42: HTTP Interceptor
The $http service of AngularJS allows us to communicate with a backend and make HTTP requests. There are cases
where we want to capture every request and manipulate it before sending it to the server. Other times we would
like to capture the response and process it before completing the call. Global http error handling can be also a good
example of such need. Interceptors are created exactly for such cases.
Section 42.1: Generic httpInterceptor step by step
Create an HTML file with the following content:
<!DOCTYPE html>
<html>
<head>
 <title>Angular Interceptor Sample</title>
 <script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
 <script src="app.js"></script>
 <script src="appController.js"></script>
 <script src="genericInterceptor.js"></script>
</head>
<body ng-app="interceptorApp">
 <div ng-controller="appController as vm">
 <button ng-click="vm.sendRequest()">Send a request</button>
 </div>
</body>
</html>
Add a JavaScript file called 'app.js':
var interceptorApp = angular.module('interceptorApp', []);
interceptorApp.config(function($httpProvider) {
 $httpProvider.interceptors.push('genericInterceptor');
});
Add another one called 'appController.js':
(function() {
 'use strict';
function appController($http) {
 var vm = this;
vm.sendRequest = function(){
 $http.get('http://google.com').then(function(response){
 console.log(response);
 });
 };
 }
angular.module('interceptorApp').controller('appController',['$http', appController]);
})();
And finally the file containing the interceptor itself 'genericInterceptor.js':
(function() {
 "use strict";
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function genericInterceptor($q) {
 this.responseError = function (response) {
 return $q.reject(response);
 };
this.requestError = function(request){
 if (canRecover(rejection)) {
 return responseOrNewPromise
 }
 return $q.reject(rejection);
 };
this.response = function(response){
 return response;
 };
this.request = function(config){
 return config;
 }
 }
angular.module('interceptorApp').service('genericInterceptor', genericInterceptor);
})();
The 'genericInterceptor' cover the possible functions which we can override adding extra behavior to our
application.
Section 42.2: Getting Started
Angular's builtin $http service allows us to send HTTP requests. Oftentime, the need arise to do things before or
after a request, for example adding to each request an authentication token or creating a generic error handling
logic.
Section 42.3: Flash message on response using http
interceptor
In the view file
In the base html (index.html) where we usually include the angular scripts or the html that is shared across the app,
leave an empty div element, the flash messages will be appearing inside this div element
<div class="flashmessage" ng-if="isVisible">
 {{flashMessage}}
</div>
Script File
In the config method of angular module, inject the httpProvider, the httpProvider has an interceptor array property,
push the custom interceptor, In the current example the custom interceptor intercepts only the response and calls
a method attached to rootScope.
var interceptorTest = angular.module('interceptorTest', []);
interceptorTest.config(['$httpProvider',function ($httpProvider) {
$httpProvider.interceptors.push(["$rootScope",function ($rootScope) {
 return { //intercept only the response
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'response': function (response)
 {
$rootScope.showFeedBack(response.status,response.data.message);
return response;
 }
 };
 }]);
}])
Since only providers can be injected into the config method of an angular module (that is httpProvider and not the
rootscope), declare the method attached to rootscope inside the run method of angular module.
Also display the message inside $timeout so that the message will have the flash property, that is disappearing
after a threshold time. In our example its 3000 ms.
interceptorTest.run(["$rootScope","$timeout",function($rootScope,$timeout){
 $rootScope.showFeedBack = function(status,message){
$rootScope.isVisible = true;
 $rootScope.flashMessage = message;
 $timeout(function(){$rootScope.isVisible = false },3000)
 }
}]);
Common pitfalls
Trying to inject $rootScope or any other services inside config method of angular module, the lifecycle of angular
app doesn't allow that and unknown provider error will be thrown. Only providers can be injected in config
method of the angular module
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Chapter 43: Session storage
Section 43.1: Handling session storage through service using
angularjs
Session storage service :
Common factory service that will save and return the saved session data based on the key.
'use strict';
/**
 * @ngdoc factory
 * @name app.factory:storageService
 * @description This function will communicate with HTML5 sessionStorage via Factory Service.
 */
app.factory('storageService', ['$rootScope', function($rootScope) {
return {
 get: function(key) {
 return sessionStorage.getItem(key);
 },
 save: function(key, data) {
 sessionStorage.setItem(key, data);
 }
 };
}]);
In controller :
Inject the storageService dependency in the controller to set and get the data from the session storage.
app.controller('myCtrl',['storageService',function(storageService) {
// Save session data to storageService
 storageService.save('key', 'value');
// Get saved session data from storageService
 var sessionData = storageService.get('key');
});
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Chapter 44: Angular MVC
In AngularJS the MVC pattern is implemented in JavaScript and HTML. The view is defined in HTML, while the
model and controller are implemented in JavaScript. There are several ways that these components can be put
together in AngularJS but the simplest form starts with the view.
Section 44.1: The Static View with controller
mvc demo
Hello World
Section 44.2: Controller Function Definition
var indexController = myApp.controller("indexController", function ($scope) {
 // Application logic goes here
});
Section 44.3: Adding information to the model
var indexController = myApp.controller("indexController", function ($scope) {
 // controller logic goes here
 $scope.message = "Hello Hacking World"
});
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Chapter 45: SignalR with AngularJS
In this article we focus on "How to create a simple project using AngularJS And SignalR", in this training you need to
know about "how create app with angularjs", "how to create/use service on angular" And basic knowledge about
SignalR" for this we recommend https://www.codeproject.com/Tips/590660/Introduction-to-SignalR).
Section 45.1: SignalR and AngularJS [ ChatProject ]
step 1: Create Project
- Application
 - app.js
 - Controllers
 - appController.js
 - Factories
 - SignalR-factory.js
- index.html
- Scripts
 - angular.js
 - jquery.js
 - jquery.signalR.min.js
- Hubs
SignalR version use: signalR-2.2.1
Step 2: Startup.cs And ChatHub.cs
Go to your "/Hubs" directory and Add 2 files [Startup.cs, ChatHub.cs]
Startup.cs
using Microsoft.Owin;
using Owin;
[assembly: OwinStartup(typeof(SignalR.Hubs.Startup))]
namespace SignalR.Hubs
{
 public class Startup
 {
 public void Configuration(IAppBuilder app)
 {
 app.MapSignalR();
 }
 }
}
ChatHub.cs
using Microsoft.AspNet.SignalR;
namespace SignalR.Hubs
{
 public class ChatHub : Hub
 {
 public void Send(string name, string message, string time)
 {
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Clients.All.broadcastMessage(name, message, time);
 }
 }
}
step 3: create angular app
Go to your "/Application" directory and Add [app.js] file
app.js
var app = angular.module("app", []);
step 4: create SignalR Factory
Go to your "/Application/Factories" directory and Add [SignalR-factory.js] file
SignalR-factory.js
app.factory("signalR", function () {
 var factory = {};
factory.url = function (url) {
 $.connection.hub.url = url;
 }
factory.setHubName = function (hubName) {
 factory.hub = hubName;
 }
factory.connectToHub = function () {
 return $.connection[factory.hub];
 }
factory.client = function () {
 var hub = factory.connectToHub();
 return hub.client;
 }
factory.server = function () {
 var hub = factory.connectToHub();
 return hub.server;
 }
factory.start = function (fn) {
 return $.connection.hub.start().done(fn);
 }
return factory;
});
step 5: update app.js
var app = angular.module("app", []);
app.run(function(signalR) {
 signalR.url("http://localhost:21991/signalr");
});
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localhost:21991/signalr | this is your SignalR Hubs Urls
step 6: add controller
Go to your "/Application/Controllers" directory and Add [appController.js] file
app.controller("ctrl", function ($scope, signalR) {
 $scope.messages = [];
 $scope.user = {};
signalR.setHubName("chatHub");
signalR.client().broadcastMessage = function (name, message, time) {
 var newChat = { name: name, message: message, time: time };
$scope.$apply(function() {
 $scope.messages.push(newChat);
 });
 };
signalR.start(function () {
 $scope.send = function () {
 var dt = new Date();
 var time = dt.getHours() + ":" + dt.getMinutes() + ":" + dt.getSeconds();
signalR.server().send($scope.user.name, $scope.user.message, time);
 }
 });
});
signalR.setHubName("chatHub") | [ChatHub] (public class) > ChatHub.cs
Note: do not insert HubName with upper Case, first letter is lower Case.
signalR.client() | this method try to connect to your hubs and get all functions in the Hubs, in this
sample we have "chatHub", to get "broadcastMessage()" function;
step 7: add index.html in route of directory
index.html
<!DOCTYPE html>
<html ng-app="app" ng-controller="ctrl">
<head>
 <meta charset="utf-8" />
 <title>SignalR Simple Chat</title>
</head>
<body>
 <form>
 <input type="text" placeholder="name" ng-model="user.name" />
 <input type="text" placeholder="message" ng-model="user.message" />
 <button ng-click="send()">send</button>
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<ul>
 <li ng-repeat="item in messages">
 <b ng-bind="item.name"></b> <small ng-bind="item.time"></small> : {{item.message}}
 </li>
 </ul>
 </form>
<script src="Scripts/angular.min.js"></script>
 <script src="Scripts/jquery-1.6.4.min.js"></script>
 <script src="Scripts/jquery.signalR-2.2.1.min.js"></script>
 <script src="signalr/hubs"></script>
 <script src="app.js"></script>
 <script src="SignalR-factory.js"></script>
</body>
</html
Result with Image
User 1 (send and receive)
User 2 (send and receive)
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Chapter 46: Migration to Angular 2+
AngularJS has been totally rewritten using the TypeScript language and renamed to just Angular.
There is a lot that can be done to an AngularJS app to ease the migration process. As the official upgrade guide
says, several "preparation steps" can be performed to refactor your app, making it better and closer to the new
Angular style.
Section 46.1: Converting your AngularJS app into a
componend-oriented structure
In the new Angular framework, Components are the main building blocks that compose the user interface. So one
of the first steps that helps an AngularJS app to be migrated to the new Angular is to refactor it into a more
component-oriented structure.
Components were also introduced in the old AngularJS starting from version 1.5+. Using Components in an
AngularJS app will not only make its structure closer to the new Angular 2+, but it will also make it more modular
and easier to maintain.
Before going further I recommend to look at the official AngularJS documentation page about Components, where
their advantages and usage are well explained.
I would rather mention some tips about how to convert the old ng-controller oriented code to the new component
oriented style.
Start breaking your your app into components
All the component-oriented apps have typically one or few components that include other sub-components. So why
not creating the first component which simply will contain your app (or a big piece of it).
Assume that we have a piece of code assigned to a controller, named UserListController, and we want to make a
component of it, which we'll name UserListComponent.
current HTML:
<div ng-controller="UserListController as listctrl">
 <ul>
 <li ng-repeat="user in myUserList">
 {{ user }}
 </li>
 </ul>
</div>
current JavaScript:
app.controller("UserListController", function($scope, SomeService) {
$scope.myUserList = ['Shin', 'Helias', 'Kalhac'];
this.someFunction = function() {
 // ...
 }
// ...
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}
new HTML:
<user-list></user-list>
new JavaScript:
app.component("UserList", {
 templateUrl: 'user-list.html',
 controller: UserListController
});
function UserListController(SomeService) {
this.myUserList = ['Shin', 'Helias', 'Kalhac'];
this.someFunction = function() {
 // ...
 }
// ...
}
Note how we are no longer injecting $scope into the controller function and we are now declaring this.myUserList
instead of $scope.myUserList;
new template file user-list.component.html:
<ul>
 <li ng-repeat="user in $ctrl.myUserList">
 {{ user }}
 </li>
</ul>
Note how we are now referring to the variable myUserList, which belongs to the controller, using
$ctrl.myUserList from the html instead of $scope.myUserList.
That is because, as you probably figured out after reading the documentation, $ctrl in the template now refers to
the controller function.
What about controllers and routes?
In case your controller was bound to the template using the routing system instead of ng-controller, so if you
have something like this:
$stateProvider
 .state('users', {
 url: '/users',
 templateUrl: 'user-list.html',
 controller: 'UserListController'
 })
 // ..
you can just change your state declaration to:
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$stateProvider
 .state('users', {
 url: '/',
 template: '<user-list></user-list>'
 })
 // ..
What's next?
Now that you have a component containing your app (whether it contains the entire application or a part of it, like a
view), you should now start to break your component into multiple nested components, by wrapping parts of it into
new sub-components, and so on.
You should start using the Component features like
Inputs and Outputs bindings
lifecycle hooks such as $onInit(), $onChanges(), etc...
After reading the Component documentation you should already know how to use all those component features,
but if you need a concrete example of a real simple app, you can check this.
Also, if inside your component's controller you have some functions that hold a lot of logic code, a good idea can be
considering to move that logic into services.
Conclusion
Adopting a component-based approach pushes your AngularJS one step closer to migrate it to the new Angular
framework, but it also makes it better and much more modular.
Of course there are a lot of other steps you can do to go further into the new Angular 2+ direction, which I will list in
the following examples.
Section 46.2: Introducing Webpack and ES6 modules
By using a module loader like Webpack we can benefit the built-in module system available in ES6 (as well as in
TypeScript). We can then use the import and export features that allow us to specify what pieces of code can we
are going to share between different parts of the application.
When we then take our applications into production, module loaders also make it easier to package them all up
into production bundles with batteries included.
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Chapter 47: AngularJS with data filter,
pagination etc
Provider example and query about display data with filter, pagination etc in Angularjs.
Section 47.1: AngularJS display data with filter, pagination
<div ng-app="MainApp" ng-controller="SampleController">
 <input ng-model="dishName" id="search" class="form-control" placeholder="Filter text">
 <ul>
 <li dir-paginate="dish in dishes | filter : dishName | itemsPerPage: pageSize" pagination-
id="flights">{{dish}}</li>
 </ul>
 <dir-pagination-controls boundary-links="true" on-page-change="changeHandler(newPageNumber)"
pagination-id="flights"></dir-pagination-controls>
</div>
<script type="text/javascript" src="angular.min.js"></script>
<script type="text/javascript" src="pagination.js"></script>
<script type="text/javascript">
var MainApp = angular.module('MainApp', ['angularUtils.directives.dirPagination'])
MainApp.controller('SampleController', ['$scope', '$filter', function ($scope, $filter) {
$scope.pageSize = 5;
$scope.dishes = [
 'noodles',
 'sausage',
 'beans on toast',
 'cheeseburger',
 'battered mars bar',
 'crisp butty',
 'yorkshire pudding',
 'wiener schnitzel',
 'sauerkraut mit ei',
 'salad',
 'onion soup',
 'bak choi',
 'avacado maki'
 ];
$scope.changeHandler = function (newPage) { };
}]);
</script>
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Chapter 48: Profiling and Performance
Section 48.1: 7 Simple Performance Improvements
1) Use ng-repeat sparingly
Using ng-repeat in views generally results in poor performance, particularly when there are nested ng-repeat's.
This is super slow!
<div ng-repeat="user in userCollection">
 <div ng-repeat="details in user">
 {{details}}
 </div>
</div>
Try to avoid nested repeats as much as possible. One way to improve the performance of ng-repeat is to use track
by $index (or some other id field). By default, ng-repeat tracks the whole object. With track by, Angular watches
the object only by the $index or object id.
<div ng-repeat="user in userCollection track by $index">
 {{user.data}}
</div>
Use other approaches like pagination, virtual scrolls, infinite scrolls or limitTo: begin whenever possible to avoid
iterating over large collections.
2) Bind once
Angular has bidirectional data binding. It comes with a cost of being slow if used too much.
Slower Performance
<!-- Default data binding has a performance cost -->
<div>{{ my.data }}</div>
Faster Performance (AngularJS >= 1.3)
<!-- Bind once is much faster -->
<div>{{ ::my.data }}</div>
<div ng-bind="::my.data"></div>
<!-- Use single binding notation in ng-repeat where only list display is needed -->
<div ng-repeat="user in ::userCollection">
 {{::user.data}}
</div>
Using the "bind once" notation tells Angular to wait for the value to stabilize after the first series of digest cycles.
Angular will use that value in the DOM, then remove all watchers so that it becomes a static value and is no longer
bound to the model.
The {{}} is much slower.
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This ng-bind is a directive and will place a watcher on the passed variable. So the ng-bind will only apply, when the
passed value does actually change.
The brackets on the other hand will be dirty checked and refreshed in every $digest, even if it's not necessary.
3) Scope functions and filters take time
AngularJS has a digest loop. All your functions are in a view and filters are executed every time the digest cycle runs.
The digest loop will be executed whenever the model is updated and it can slow down your app (filter can be hit
multiple times before the page is loaded).
Avoid this:
<div ng-controller="bigCalulations as calc">
 <p>{{calc.calculateMe()}}</p>
 <p>{{calc.data | heavyFilter}}</p>
</div>
Better approach
<div ng-controller="bigCalulations as calc">
 <p>{{calc.preCalculatedValue}}</p>
 <p>{{calc.data | lightFilter}}</p>
</div>
Where the controller can be:
app.controller('bigCalulations', function(valueService) {
 // bad, because this is called in every digest loop
 this.calculateMe = function() {
 var t = 0;
 for(i = 0; i < 1000; i++) {
 t += i;
 }
 return t;
 }
 // good, because this is executed just once and logic is separated in service to keep the
controller light
 this.preCalulatedValue = valueService.valueCalculation(); // returns 499500
});
4) Watchers
Watchers tremendously drop performance. With more watchers, the digest loop will take longer and the UI will
slow down. If the watcher detects change, it will kick off the digest loop and re-render the view.
There are three ways to do manual watching for variable changes in Angular.
$watch() - watches for value changes
$watchCollection() - watches for changes in collection (watches more than regular $watch)
$watch(..., true) - Avoid this as much as possible, it will perform "deep watch" and will decline the performance
(watches more than watchCollection)
Note that if you are binding variables in the view you are creating new watches - use {{::variable}} to prevent
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creating a watch, especially in loops.
As a result you need to track how many watchers you are using. You can count the watchers with this script (credit
to @Words Like Jared Number of watchers)
(function() {
 var root = angular.element(document.getElementsByTagName('body')),
 watchers = [],
 f = function(element) {
 angular.forEach(['$scope', '$isolateScope'], function(scopeProperty) {
 if(element.data() && element.data().hasOwnProperty(scopeProperty)) {
 angular.forEach(element.data()[scopeProperty].$$watchers, function(watcher) {
 watchers.push(watcher);
 });
 }
 });
angular.forEach(element.children(), function(childElement) {
 f(angular.element(childElement));
 });
 };
f(root);
// Remove duplicate watchers
 var watchersWithoutDuplicates = [];
 angular.forEach(watchers, function(item) {
 if(watchersWithoutDuplicates.indexOf(item) < 0) {
 watchersWithoutDuplicates.push(item);
 }
 });
 console.log(watchersWithoutDuplicates.length);
})();
5) ng-if / ng-show
These functions are very similar in behavior. ng-if removes elements from the DOM while ng-show only hides the
elements but keeps all handlers. If you have parts of the code you do not want to show, use ng-if.
It depends on the type of usage, but often one is more suitable than the other.
If the element is not needed, use ng-if
To quickly toggle on/off, use ng-show/ng-hide
<div ng-repeat="user in userCollection">
 <p ng-if="user.hasTreeLegs">I am special<!-- some complicated DOM --></p>
 <p ng-show="user.hasSubscribed">I am awesome<!-- switch this setting on and off --></p>
</div>
If in doubt - use ng-if and test!
6) Disable debugging
By default, bind directives and scopes leave extra classes and markup in the code to assist with various debugging
tools. Disabling this option means that you no longer render these various elements during the digest cycle.
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angular.module('exampleApp', []).config(['$compileProvider', function ($compileProvider) {
 $compileProvider.debugInfoEnabled(false);
}]);
7) Use dependency injection to expose your resources
Dependency Injection is a software design pattern in which an object is given its dependencies, rather than the
object creating them itself. It is about removing the hard-coded dependencies and making it possible to change
them whenever needed.
You might wonder about the performance cost associated with such string parsing of all injectable functions.
Angular takes care of this by caching the $inject property after the first time. So this doesn’t happen every time a
function needs to be invoked.
PRO TIP: If you are looking for the approach with the best performance, go with the $inject property annotation
approach. This approach entirely avoids the function definition parsing because this logic is wrapped within the
following check in the annotate function: if (!($inject = fn.$inject)). If $inject is already available, no parsing required!
var app = angular.module('DemoApp', []);
var DemoController = function (s, h) {
 h.get('https://api.github.com/users/angular/repos').success(function (repos) {
 s.repos = repos;
 });
}
// $inject property annotation
DemoController['$inject'] = ['$scope', '$http'];
app.controller('DemoController', DemoController);
PRO TIP 2: You can add an ng-strict-di directive on the same element as ng-app to opt into strict DI mode which
will throw an error whenever a service tries to use implicit annotations. Example:
<html ng-app="DemoApp" ng-strict-di>
Or if you use manual bootstrapping:
angular.bootstrap(document, ['DemoApp'], {
 strictDi: true
});
Section 48.2: Bind Once
Angular has reputation for having awesome bidirectional data binding. By default, Angular continuously
synchronizes values bound between model and view components any time data changes in either the model or
view component.
This comes with a cost of being a bit slow if used too much. This will have a larger performance hit:
Bad performance: {{my.data}}
Add two colons :: before the variable name to use one-time binding. In this case, the value only gets updated once
my.data is defined. You are explicitly pointing not to watch for data changes. Angular won't perform any value
checks, resulting with fewer expressions being evaluated on each digest cycle.
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Good performance examples using one-time binding
{{::my.data}}
<span ng-bind="::my.data"></span>
<span ng-if="::my.data"></span>
<span ng-repeat="item in ::my.data">{{item}}</span>
<span ng-class="::{ 'my-class': my.data }"></div>
Note: This however removes the bi-directional data binding for my.data, so whenever this field changes in your
application, the same won't be reflected in the view automatically. So use it only for values that won't change
throughout the lifespan of your application.
Section 48.3: ng-if vs ng-show
These functions are very similar in behaviour. The difference is that ng-if removes elements from the DOM. If
there are large parts of the code that will not be shown, then ng-if is the way to go. ng-show will only hide the
elements but will keep all the handlers.
ng-if
The ngIf directive removes or recreates a portion of the DOM tree based on an expression. If the expression
assigned to ngIf evaluates to a false value then the element is removed from the DOM, otherwise a clone of the
element is reinserted into the DOM.
ng-show
The ngShow directive shows or hides the given HTML element based on the expression provided to the ngShow
attribute. The element is shown or hidden by removing or adding the ng-hide CSS class onto the element.
Example
<div ng-repeat="user in userCollection">
 <p ng-if="user.hasTreeLegs">I am special
 <!-- some complicated DOM -->
 </p>
 <p ng-show="user.hasSubscribed">I am aweosme
 <!-- switch this setting on and off -->
 </p>
</div>
Conclusion
It depends from the type of usage, but often one is more suitable than the other (e.g., if 95% of the time the
element is not needed, use ng-if; if you need to toggle the DOM element's visibility, use ng-show).
When in doubt, use ng-if and test!
Note: ng-if creates a new isolated scope, whereas ng-show and ng-hide don't. Use $parent.property if parent
scope property is not directly accessible in it.
Section 48.4: Watchers
Watchers needed for watch some value and detect that this value is changed.
After call $watch() or $watchCollection new watcher add to internal watcher collection in current scope.
So, what is watcher?
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Watcher is a simple function, which is called on every digest cycle, and returns some value. Angular checks the
returned value, if it is not the same as it was on the previous call - a callback that was passed in second parameter
to function $watch() or $watchCollection will be executed.
(function() {
 angular.module("app", []).controller("ctrl", function($scope) {
 $scope.value = 10;
 $scope.$watch(
 function() { return $scope.value; },
 function() { console.log("value changed"); }
 );
 }
})();
Watchers are performance killers. The more watchers you have, the longer they take to make a digest loop, the
slower UI. If a watcher detects changes, it will kick off the digest loop (recalculation on all screen)
There are three ways to do manual watch for variable changes in Angular.
$watch() - just watches for value changes
$watchCollection() - watches for changes in collection (watches more than regular $watch)
$watch(..., true) - Avoid this as much as possible, it will perform "deep watch" and will kill the performance
(watches more than watchCollection)
Note that if you are binding variables in the view, you are creating new watchers - use {{::variable}} not to create
watcher, especially in loops
As a result you need to track how many watchers are you using. You can count the watchers with this script (credit
to @Words Like Jared - How to count total number of watches on a page?
(function() {
 var root = angular.element(document.getElementsByTagName("body")),
 watchers = [];
var f = function(element) {
angular.forEach(["$scope", "$isolateScope"], function(scopeProperty) {
 if(element.data() && element.data().hasOwnProperty(scopeProperty)) {
 angular.forEach(element.data()[scopeProperty].$$watchers, function(watcher) {
 watchers.push(watcher);
 });
 }
 });
angular.forEach(element.children(), function(childElement) {
 f(angular.element(childElement));
 });
};
f(root);
// Remove duplicate watchers
 var watchersWithoutDuplicates = [];
 angular.forEach(watchers, function(item) {
 if(watchersWithoutDuplicates.indexOf(item) < 0) {
 watchersWithoutDuplicates.push(item);
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}
 });
console.log(watchersWithoutDuplicates.length);
})();
If you don't want to create your own script, there is an open source utility called ng-stats that uses a real-time chart
embedded into the page to give you insight into the number of watches Angular is managing, as well as the
frequency and duration of digest cycles over time. The utility exposes a global function named showAngularStats
that you can call to configure how you want the chart to work.
showAngularStats({
 "position": "topleft",
 "digestTimeThreshold": 16,
 "autoload": true,
 "logDigest": true,
 "logWatches": true
});
The example code above displays the following chart on the page automatically (interactive demo).
Section 48.5: Always deregister listeners registered on other
scopes other than the current scope
You must always unregister scopes other then your current scope as shown below:
//always deregister these
$rootScope.$on(...);
$scope.$parent.$on(...);
You don't have to deregister listners on current scope as angular would take care of it:
//no need to deregister this
$scope.$on(...);
$rootScope.$on listeners will remain in memory if you navigate to another controller. This will create a memory
leak if the controller falls out of scope.
Don't
angular.module('app').controller('badExampleController', badExample);
badExample.$inject = ['$scope', '$rootScope'];
function badExample($scope, $rootScope) {
 $rootScope.$on('post:created', function postCreated(event, data) {});
}
Do
angular.module('app').controller('goodExampleController', goodExample);
goodExample.$inject = ['$scope', '$rootScope'];
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function goodExample($scope, $rootScope) {
 var deregister = $rootScope.$on('post:created', function postCreated(event, data) {});
$scope.$on('$destroy', function destroyScope() {
 deregister();
 });
}
Section 48.6: Scope functions and filters
AngularJS has digest loop and all your functions in a view and filters are executed every time the digest cycle is run.
The digest loop will be executed whenever the model is updated and it can slow down your app (filter can be hit
multiple times, before the page is loaded).
You should avoid this:
<div ng-controller="bigCalulations as calc">
 <p>{{calc.calculateMe()}}</p>
 <p>{{calc.data | heavyFilter}}</p>
</div>
Better approach
<div ng-controller="bigCalulations as calc">
 <p>{{calc.preCalculatedValue}}</p>
 <p>{{calc.data | lightFilter}}</p>
</div>
Where controller sample is:
.controller("bigCalulations", function(valueService) {
 // bad, because this is called in every digest loop
 this.calculateMe = function() {
 var t = 0;
 for(i = 0; i < 1000; i++) {
 t = t + i;
 }
 return t;
 }
 //good, because it is executed just once and logic is separated in service to keep the
controller light
 this.preCalulatedValue = valueService.caluclateSumm(); // returns 499500
});
Section 48.7: Debounce Your Model
<div ng-controller="ExampleController">
 <form name="userForm">
 Name:
 <input type="text" name="userName"
 ng-model="user.name"
 ng-model-options="{ debounce: 1000 }" />
 <button ng-click="userForm.userName.$rollbackViewValue();
user.name=''">Clear</button><br />
 </form>
 <pre>user.name = </pre>
</div>
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The above example we are setting a debounce value of 1000 milliseconds which is 1 second. This is a considerable
delay, but will prevent the input from repeatedly thrashing ng-model with many $digest cycles.
By using debounce on your input fields and anywhere else where an instant update is not required, you can
increase the performance of your Angular apps quite substantially. Not only can you delay by time, but you can also
delay when the action gets triggered. If you don’t want to update your ng-model on every keystroke, you can also
update on blur as well.
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Chapter 49: Performance Profiling
Section 49.1: All About Profiling
What is Profiling?
By definition Profiling is a form of dynamic program analysis that measures, for example, the space (memory) or
time complexity of a program, the usage of particular instructions, or the frequency and duration of function calls.
Why is it necessary?
Profiling is important because you can’t optimise effectively until you know what your program is spending most of
its time doing. Without measuring your program execution time (profiling), you won’t know if you’ve actually
improved it.
Tools and Techniques :
1.
Chrome's in-built dev tools
This includes a comprehensive set of tools to be used for profiling.You can go deep to find out bottlenecks in
your javascript file, css files, animations, cpu consumption, memory leaks, network, security etc.
Make a Timeline recording and look for suspiciously long Evaluate Script events. If you find any, you can
enable the JS Profiler and re-do your recording to get more detailed information about exactly which JS
functions were called and how long each took. Read more...
2.
FireBug (use with Firefox)
3.
Dynatrace (use with IE)
4.
Batarang (use with Chrome)
It's an outdated add-on for chrome browser though it's stable and can be used to monitor models,
performance, dependencies for an angular application. It works fine for small scale application and can give
you an insight of what does scope variable holds at various levels. It tells you about active watchers, watch
expressions, watch collections in the app.
5.
Watcher (use with Chrome)
Nice and simplistic UI to count the number of watchers in a Angular app.
6.
Use the following code to manually find out the number of watchers in your angular app (credit to @Words
Like Jared Number of watchers)
(function() {
 var root = angular.element(document.getElementsByTagName('body')),
 watchers = [],
 f = function(element) {
 angular.forEach(['$scope', '$isolateScope'], function(scopeProperty) {
 if(element.data() && element.data().hasOwnProperty(scopeProperty)) {
 angular.forEach(element.data()[scopeProperty].$$watchers, function(watcher) {
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watchers.push(watcher);
 });
 }
 });
angular.forEach(element.children(), function(childElement) {
 f(angular.element(childElement));
 });
 };
f(root);
// Remove duplicate watchers
 var watchersWithoutDuplicates = [];
 angular.forEach(watchers, function(item) {
 if(watchersWithoutDuplicates.indexOf(item) < 0) {
 watchersWithoutDuplicates.push(item);
 }
 });
 console.log(watchersWithoutDuplicates.length);
})();
7.
There are several online tools/websites available which facilitates wide range of functionalities to create a
profile of your application.
One such site is : https://www.webpagetest.org/
With this you can run a free website speed test from multiple locations around the globe using real browsers
(IE and Chrome) and at real consumer connection speeds. You can run simple tests or perform advanced
testing including multi-step transactions, video capture, content blocking and much more.
Next Steps:
Done with Profiling. It only brings you half way down the road. The very next task is to actually turn your findings
into action items to optimise your application. See this documentation on how you can improve the performance of
your angular app with simple tricks.
Happy Coding :)
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Chapter 50: Debugging
Section 50.1: Using ng-inspect chrome extension
ng-inspect is a light weight Chrome extension for debugging AngularJS applications.
When a node is selected from the elements panel, the scope related info is displayed in the ng-inspect panel.
Exposes few global variables for quick access of scope/isolateScope.
$s -- scope of the selected node
$is -- isolateScope of the selected node
$el -- jQuery element reference of the selected node (requiers jQuery)
$events -- events present on the selected node (requires jQuery)
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Provides easy access to Services/Factories.
Use $get() to retrieve the instance of a service/factory by name.
Performance of the application can be monitored by counting the no.of scopes,isolateScopes, watchers and
listeners on the application.
Use $count() to get the count of scopes, isolateScopes, watchers and listeners.
Note: This extension will work only when the debugInfo is enabled.
Download ng-inspect here
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Section 50.2: Getting the Scope of element
In an angular app everything goes around scope, if we could get an elements scope then it is easy to debug the
angular app. How to access the scope of element:
angular.element(myDomElement).scope();
e.g.
angular.element(document.getElementById('yourElementId')).scope() //accessing by ID
Getting the scope of the controller:
angular.element('[ng-controller=ctrl]').scope()
Another easy way to access a DOM element from the console (as jm mentioned) is to click on it in the 'elements'
tab, and it automatically gets stored as $0.
angular.element($0).scope();
Section 50.3: Basic debugging in markup
Scope testing & output of model
<div ng-app="demoApp" ng-controller="mainController as ctrl">
 {{$id}}
 <ul>
 <li ng-repeat="item in ctrl.items">
 {{$id}}<br/>
 {{item.text}}
 </li>
 </ul>
 {{$id}}
 <pre>
 {{ctrl.items | json : 2}}
 </pre>
</div>
angular.module('demoApp', [])
.controller('mainController', MainController);
function MainController() {
 var vm = this;
 vm.items = [{
 id: 0,
 text: 'first'
 },
 {
 id: 1,
 text: 'second'
 },
 {
 id: 2,
 text: 'third'
 }];
}
Sometimes it can help to see if there is a new scope to fix scoping issues. $scope.$id can be used in an expression
everywhere in your markup to see if there is a new $scope.
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In the example you can see that outside of the ul-tag is the same scope ($id=2) and inside the ng-repeat there are
new child scopes for each iteration.
An output of the model in a pre-tag is useful to see the current data of your model. The json filter creates a nice
looking formatted output. The pre-tag is used because inside that tag any new-line character \n will be correctly
displayed.
demo
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Chapter 51: Unit tests
Section 51.1: Unit test a component (1.5+)
Component code:
angular.module('myModule', []).component('myComponent', {
 bindings: {
 myValue: '<'
 },
 controller: function(MyService) {
 this.service = MyService;
 this.componentMethod = function() {
 return 2;
 };
 }
});
The test:
describe('myComponent', function() {
 var component;
var MyServiceFake = jasmine.createSpyObj(['serviceMethod']);
beforeEach(function() {
 module('myModule');
 inject(function($componentController) {
 // 1st - component name, 2nd - controller injections, 3rd - bindings
 component = $componentController('myComponent', {
 MyService: MyServiceFake
 }, {
 myValue: 3
 });
 });
 });
/** Here you test the injector. Useless. */
it('injects the binding', function() {
 expect(component.myValue).toBe(3);
 });
it('has some cool behavior', function() {
 expect(component.componentMethod()).toBe(2);
 });
});
Run!
Section 51.2: Unit test a filter
Filter code:
angular.module('myModule', []).filter('multiplier', function() {
 return function(number, multiplier) {
 if (!angular.isNumber(number)) {
 throw new Error(number + " is not a number!");
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}
 if (!multiplier) {
 multiplier = 2;
 }
 return number * multiplier;
 }
});
The test:
describe('multiplierFilter', function() {
 var filter;
beforeEach(function() {
 module('myModule');
 inject(function(multiplierFilter) {
 filter = multiplierFilter;
 });
 });
it('multiply by 2 by default', function() {
 expect(filter(2)).toBe(4);
 expect(filter(3)).toBe(6);
 });
it('allow to specify custom multiplier', function() {
 expect(filter(2, 4)).toBe(8);
 });
it('throws error on invalid input', function() {
 expect(function() {
 filter(null);
 }).toThrow();
 });
});
Run!
Remark: In the inject call in the test, your filter needs to be specified by its name + Filter. The cause for this is that
whenever you register a filter for your module, Angular register it with a Filter appended to its name.
Section 51.3: Unit test a service
Service Code
angular.module('myModule', [])
 .service('myService', function() {
 this.doSomething = function(someNumber) {
 return someNumber + 2;
 }
 });
The test
describe('myService', function() {
 var myService;
 beforeEach(function() {
 module('myModule');
 inject(function(_myService_) {
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myService = _myService_;
 });
 });
 it('should increment `num` by 2', function() {
 var result = myService.doSomething(4);
 expect(result).toEqual(6);
 });
});
Run!
Section 51.4: Unit test a controller
Controller code:
angular.module('myModule', [])
 .controller('myController', function($scope) {
 $scope.num = 2;
 $scope.doSomething = function() {
 $scope.num += 2;
 }
 });
The test:
describe('myController', function() {
 var $scope;
 beforeEach(function() {
 module('myModule');
 inject(function($controller, $rootScope) {
 $scope = $rootScope.$new();
 $controller('myController', {
 '$scope': $scope
 })
 });
 });
 it('should increment `num` by 2', function() {
 expect($scope.num).toEqual(2);
 $scope.doSomething();
 expect($scope.num).toEqual(4);
 });
});
Run!
Section 51.5: Unit test a directive
Directive code
angular.module('myModule', [])
 .directive('myDirective', function() {
 return {
 template: '<div>{{greeting}} {{name}}!</div>',
 scope: {
 name: '=',
 greeting: '@'
 }
 };
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});
The test
describe('myDirective', function() {
 var element, scope;
 beforeEach(function() {
 module('myModule');
 inject(function($compile, $rootScope) {
 scope = $rootScope.$new();
 element = angular.element("<my-directive name='name' greeting='Hello'></my-directive>");
 $compile(element)(scope);
 /* PLEASE NEVER USE scope.$digest(). scope.$apply use a protection to avoid to run a digest
loop when there is already one, so, use scope.$apply() instead. */
 scope.$apply();
 })
 });
it('has the text attribute injected', function() {
 expect(element.html()).toContain('Hello');
 });
it('should have proper message after scope change', function() {
 scope.name = 'John';
 scope.$apply();
 expect(element.html()).toContain("John");
 scope.name = 'Alice';
 expect(element.html()).toContain("John");
 scope.$apply();
 expect(element.html()).toContain("Alice");
 });
});
Run!
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Chapter 52: AngularJS gotchas and traps
Section 52.1: Things to do when using html5Mode
When using html5Mode([mode]) it is necessary that:
1.
You specify the base URL for the application with a <base href=""> in the head of your index.html.
2.
It is important that the base tag comes before any tags with url requests. Otherwise, this might result in this
error - "Resource interpreted as stylesheet but transferred with MIME type text/html". For
example:
<head>
 <meta charset="utf-8">
 <title>Job Seeker</title>
<base href="/">
<link rel="stylesheet" href="bower_components/bootstrap/dist/css/bootstrap.css" />
 <link rel="stylesheet" href="/styles/main.css">
</head>
3.
If you do no want to specify a base tag, configure $locationProvider to not require a base tag by passing a
definition object with requireBase:false to $locationProvider.html5Mode() like this:
$locationProvider.html5Mode({
 enabled: true,
 requireBase: false
});
4.
In order to support direct loading of HTML5 URLs, you need to enabler server-side URL rewriting. From
AngularJS / Developer Guide / Using $location
Using this mode requires URL rewriting on server side, basically you have to rewrite all your links to
entry point of your application (e.g. index.html). Requiring a <base> tag is also important for this
case, as it allows Angular to differentiate between the part of the url that is the application base
and the path that should be handled by the application.
An excellent resource for request rewriting examples for various HTTP server implementations can be found
in the ui-router FAQ - How to: Configure your server to work with html5Mode. For example, Apache
RewriteEngine on
# Don't rewrite files or directories
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
# Rewrite everything else to index.html to allow html5 state links
RewriteRule ^ index.html [L]
nginx
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server {
 server_name my-app;
root /path/to/app;
location / {
 try_files $uri $uri/ /index.html;
 }
 }
Express
var express = require('express');
 var app = express();
app.use('/js', express.static(__dirname + '/js'));
 app.use('/dist', express.static(__dirname + '/../dist'));
 app.use('/css', express.static(__dirname + '/css'));
 app.use('/partials', express.static(__dirname + '/partials'));
app.all('/*', function(req, res, next) {
 // Just send the index.html for other files to support HTML5Mode
 res.sendFile('index.html', { root: __dirname });
 });
app.listen(3006); //the port you want to use
Section 52.2: Two-way data binding stops working
One should have in mind that:
1.
2.
Angular's data binding relies on JavaScript’s prototypal inheritance, thus it's subject to variable shadowing.
A child scope normally prototypically inherits from its parent scope. One exception to this rule is a directive
which has an isolated scope as it doesn't prototypically inherit.
3.
There are some directives which create a new child scope: ng-repeat, ng-switch, ng-view, ng-if, ng-
controller, ng-include, etc.
This means that when you try to two-way bind some data to a primitive which is inside of a child scope (or vice-
versa), things may not work as expected. Here's an example of how easily is to "break" AngularJS.
This issue can easily be avoided following these steps:
1.
2.
3.
Have a "." inside your HTML template whenever you bind some data
Use controllerAs syntax as it promotes the use of binding to a "dotted" object
$parent can be used to access parent scope variables rather than child scope. like inside ng-if we can use
ng-model="$parent.foo"..
An alternative for the above is to bind ngModel to a getter/setter function that will update the cached version of the
model when called with arguments, or return it when called without arguments. In order to use a getter/setter
function, you need to add ng-model-options="{ getterSetter: true }" to the element with the ngModal
attribute, and to call the getter function if you want to display its value in expression (Working example).
Example
View:
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<div ng-app="myApp" ng-controller="MainCtrl">
 <input type="text" ng-model="foo" ng-model-options="{ getterSetter: true }">
 <div ng-if="truthyValue">
 <!-- I'm a child scope (inside ng-if), but i'm synced with changes from the outside scope -->
 <input type="text" ng-model="foo">
 </div>
 <div>$scope.foo: {{ foo() }}</div>
</div>
Controller:
angular.module('myApp', []).controller('MainCtrl', ['$scope', function($scope) {
 $scope.truthyValue = true;
var _foo = 'hello'; // this will be used to cache/represent the value of the 'foo' model
$scope.foo = function(val) {
 // the function return the the internal '_foo' varibale when called with zero arguments,
 // and update the internal `_foo` when called with an argument
 return arguments.length ? (_foo = val) : _foo;
 };
}]);
Best Practice: It's best to keep getters fast because Angular is likely to call them more frequently than other parts
of your code (reference).
Section 52.3: 7 Deadly Sins of AngularJS
Below is the list of some mistakes that developers often make during the use of AngularJS functionalities, some
learned lessons and solutions to them.
1. Manipulating DOM through the controller
It's legal, but must be avoided. Controllers are the places where you define your dependencies, bind your data to
the view and make further business logic. You can technically manipulate the DOM in a controller, but whenever
you need same or similar manipulation in another part of your app, another controller will be needed. So the best
practice of this approach is creating a directive that includes all manipulations and use the directive throughout
your app. Hence, the controller leaves the view intact and does it's job. In a directive, linking function is the best
place to manipulate the DOM. It has full access to the scope and element, so using a directive, you can also take the
advantage of reusability.
link: function($scope, element, attrs) {
 //The best place to manipulate DOM
}
You can access DOM elements in linking function through several ways, such as the element parameter,
angular.element() method, or pure Javascript.
2. Data binding in transclusion
AngularJS is famous with its two-way data binding. However you may encounter sometimes that your data is only
one-way bound inside directives. Stop there, AngularJS is not wrong but probably you. Directives are a little
dangerous places since child scopes and isolated scopes are involved. Assume you have the following directive with
one transclusion
<my-dir>
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<my-transclusion>
 </my-transclusion>
</my-dir>
And inside my-transclusion, you have some elements which are bound to the data in the outer scope.
<my-dir>
 <my-transclusion>
 <input ng-model="name">
 </my-transclusion>
</my-dir>
The above code will not work correctly. Here, transclusion creates a child scope and you can get the name variable,
right, but whatever change you make to this variable will stay there. So, you can truly acces this variable as
$parent.name. However, this use might not be the best practice. A better approach would be wrapping the
variables inside an object. For example, in the controller you can create:
$scope.data = {
 name: 'someName'
}
Then in the transclusion, you can access this variable via 'data' object and see that two-way binding works perfectly!
<input ng-model="data.name">
Not only in transclusions, but throughout the app, it's a good idea to use the dotted notation.
3. Multiple directives together
It is actually legal to use two directives together within the same element, as long as you obey by the rule: two
isolated scopes cannot exist on the same element. Generally speaking, when creating a new custom directive, you
allocate an isolated scope for easy parameter passing. Assuming that the directives myDirA and myDirB have
isoleted scopes and myDirC has not, following element will be valid:
<input my-dir-a my-dirc>
whereas the following element will cause console error:
<input my-dir-a my-dir-b>
Therefore, directives must be used wisely, taking the scopes into consideration.
4. Misuse of $emit
$emit, $broadcast and $on, these work in a sender-receiver principle. In others words, they are a means of
communication between controllers. For example, the following line emits the 'someEvent' from controller A, to be
catched by the concerned controller B.
$scope.$emit('someEvent', args);
And the following line catches the 'someEvent'
$scope.$on('someEvent', function(){});
So far everything seems perfect. But remember that, if the controller B is not invoked yet, the event will not be
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caught, which means both emitter and receiver controllers have to be invoked to get this working. So again, if you
are not sure that you definitely have to use $emit, building a service seems a better way.
5. Misuse of $scope.$watch
$scope.$watch is used for watching a variable change. Whenever a variable has changed, this method is invoked.
However, one common mistake done is changing the variable inside $scope.$watch. This will cause inconsistency
and infinite $digest loop at some point.
$scope.$watch('myCtrl.myVariable', function(newVal) {
 this.myVariable++;
});
So in the above function, make sure you have no operations on myVariable and newVal.
6. Binding methods to views
This is one of the deadlisest sins. AngularJS has two-way binding, and whenever something changes, the views are
updated many many times. So, if you bind a method to an attribute of a view, that method might potentially be
called a hundred times, which also drives you crazy during debugging. However, there are only some attributes that
are built for method binding, such as ng-click, ng-blur, ng-on-change, etc, that expect methods as paremeter. For
instance, assume you have the following view in your markup:
<input ng-disabled="myCtrl.isDisabled()" ng-model="myCtrl.name">
Here you check the disabled status of the view via the method isDisabled. In the controller myCtrl, you have:
vm.isDisabled = function(){
 if(someCondition)
 return true;
 else
 return false;
}
In theory, it may seem correct but technically this will cause an overload, since the method will run countless times.
In order to resolve this, you should bind a variable. In your controller, the following variable must exist:
vm.isDisabled
You can initiate this variable again in the activation of the controller
if(someCondition)
 vm.isDisabled = true
else
 vm.isDisabled = false
If the condition is not stable, you may bind this to another event. Then you should bind this variable to the view:
<input ng-disabled="myCtrl.isDisabled" ng-model="myCtrl.name">
Now, all the attributes of the view have what they expect and the methods will run only whenever needed.
7. Not using Angular's functionalities
AngularJS provides great convenience with some of its functionalities, not only simplifying your code but also
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making it more efficient. Some of these features are listed below:
1.
2.
3.
4.
5.
6.
angular.forEach for the loops (Caution, you can't "break;" it, you can only prevent getting into the body, so
consider performance here.)
angular.element for DOM selectors
angular.copy: Use this when you should not modify the main object
Form validations are already awesome. Use dirty, pristine, touched, valid, required and so on.
Besides Chrome debugger, use remote debugging for mobile development too.
And make sure you use Batarang. It's a free Chrome extension where you can easily inspect scopes
.
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Credits
Thank you greatly to all the people from Stack Overflow Documentation who helped provide this content,
more changes can be sent to web@petercv.com for new content to be published or updated
Aayushi Jain
Abdellah Alaoui
Adam Harrison
Aeolingamenfel
Ajeet Lakhani
Alon Eitan
Alvaro Vazquez
Aman
Andrea
Anfelipe
Anirudha
Ankit
AnonDCX
Aron
Ashok choudhary
Ashwin Ramaswami
atul mishra
AWolf
Ayan
BarakD
Bon Macalindong
Bouraoui KACEM
casraf
CENT1PEDE
chatuur
Cosmin Ababei
Dania
Daniel
Daniel Molin
daniellmb
David G.
Deepak Bansal
developer033
DillonChanis
Divya Jain
doctorsherlock
DotBot
Dr. Cool
Durgpal Singh
Ed Hinchliffe
elliot
Eric Siebeneich
fantarama
Faruk Yazıcı
Filipe Amaral
Flash
fracz
Chapter 28
Chapter 17
Chapters 4 and 14
Chapters 9 and 14
Chapter 48
Chapters 3, 4, 6, 23, 24, 48 and 52
Chapters 17 and 24
Chapter 50
Chapter 20
Chapter 48
Chapter 48
Chapter 2
Chapter 17
Chapter 4
Chapter 44
Chapter 48
Chapter 48
Chapters 4 and 50
Chapter 4
Chapter 3
Chapters 2, 4 and 14
Chapters 12 and 15
Chapter 6
Chapters 4 and 38
Chapter 14
Chapter 52
Chapter 48
Chapter 6
Chapter 48
Chapter 48
Chapter 1
Chapters 18 and 49
Chapter 9
Chapter 4
Chapters 4, 26 and 27
Chapter 52
Chapter 24
Chapters 4, 14, 25 and 48
Chapter 48
Chapter 9
Chapters 36 and 51
Chapter 4
Chapter 23
Chapter 52
Chapter 6
Chapter 17
Chapter 51
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Chapter 6
Gaara
Chapter 51
Gabriel Pires
Chapter 19
ganqqwerty
Chapter 23
garyx
Chapter 17
Gavishiddappa Gadagi
Chapter 19
georgeawg
Chapter 5
Gourav Garg
Chapters 14 and 48
Grundy
Chapter 9
gustavohenke
Chapter 1
H. Pauwelyn
Chapter 33
H.T
Chapters 3 and 17
Hubert Grzeskowiak
Chapter 1
Igor Raush
Chapter 4
IncrediApp
Chapter 42
Istvan Reiter
Chapters 39 and 48
JanisP
Chapter 14
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Chapters 36 and 38
jaredsk
Chapter 1
Jeroen
Chapter 48
jhampton
Chapters 16 and 26
Jim
Chapter 6
Jinw
Chapter 8
jitender
Chapter 6
jkris
Chapters 3 and 19
John F.
Chapter 4
kelvinelove
Chapter 4
Krupesh Kotecha
Chapters 17 and 22
Lex
Chapters 4, 14, 36 and 38
Liron Ilayev
Chapters 7 and 29
Lucas L
Chapter 3
M. Junaid Salaat
Chapter 4
m.e.conroy
Chapter 48
M22an
Chapter 1
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Chapter 45
Maher
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Chapter 29
Manikandan Velayutham Chapter 28
Mansouri
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Matthew Green
MeanMan
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Mitul
MoLow
Muli Yulzary
Nad Flores
Naga2Raja
Nemanja Trifunovic
ngLover
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Nico
Nikos Paraskevopoulos
Chapter 3
Chapter 14
Chapters 9, 14 and 48
Chapter 42
Chapters 1, 4, 22, 23, 30, 31 and 40
Chapter 4
Chapters 20, 35 and 36
Chapter 41
Chapter 14
Chapter 4
Chapter 1
Chapters 4 and 52
Chapter 21
Chapter 48
Chapters 9, 29 and 51
Chapter 13
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Nishant123
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Pat
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redunderthebed
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ronapelbaum
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Sender
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shaN
shane
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Sunil Lama
superluminary
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timbo
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Umesh Shende
user3632710
Ven
Vinay K
vincentvanjoe
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Yasin Patel
Yuri Blanc
Ze Rubeus
ziaulain
zucker
Chapter 17
Chapter 2
Chapter 20
Chapter 47
Chapter 37
Chapter 10
Chapter 1
Chapter 1
Chapter 52
Chapter 4
Chapter 36
Chapters 14 and 19
Chapter 6
Chapters 3 and 14
Chapter 3
Chapter 4
Chapters 1, 4 and 23
Chapters 19, 21, 22, 23, 37 and 43
Chapter 51
Chapter 33
Chapters 21 and 48
Chapter 7
Chapter 26
Chapters 6, 24, 33 and 48
Chapter 21
Chapter 23
Chapter 21
Chapter 46
Chapters 1 and 22
Chapter 1
Chapters 4, 19, 23, 24 and 34
Chapter 1
Chapters 10 and 11
Chapters 4 and 48
Chapter 14
Chapters 1, 4 and 23
Chapter 4
Chapter 28
Chapter 48
Chapter 1
Chapter 50
Chapter 48
Chapter 4
Chapters 1 and 48
Chapter 6
Chapter 48
Chapter 32
Chapters 26 and 29
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