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8c763fb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | // Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Management.Automation;
using System.Management.Automation.Internal;
namespace Microsoft.PowerShell.Commands.Internal.Format
{
/// <summary>
/// Internal class to manage the grouping algorithm for the
/// format-xxx commands.
/// </summary>
internal sealed class GroupingInfoManager
{
/// <summary>
/// Initialize with the grouping property data.
/// </summary>
/// <param name="groupingExpression">Name of the grouping property.</param>
/// <param name="displayLabel">Display name of the property.</param>
internal void Initialize(PSPropertyExpression groupingExpression, string displayLabel)
{
_groupingKeyExpression = groupingExpression;
_label = displayLabel;
}
internal object CurrentGroupingKeyPropertyValue
{
get { return _currentGroupingKeyPropertyValue; }
}
internal string GroupingKeyDisplayName
{
get
{
if (_label != null)
return _label;
return _groupingKeyDisplayName;
}
}
/// <summary>
/// Compute the string value of the grouping property.
/// </summary>
/// <param name="so">Object to use to compute the property value.</param>
/// <returns>True if there was an update.</returns>
internal bool UpdateGroupingKeyValue(PSObject so)
{
if (_groupingKeyExpression == null)
return false;
List<PSPropertyExpressionResult> results = _groupingKeyExpression.GetValues(so);
// if we have more that one match, we have to select the first one
if (results.Count > 0 && results[0].Exception == null)
{
// no exception got thrown, so we can update
object newValue = results[0].Result;
object oldValue = _currentGroupingKeyPropertyValue;
_currentGroupingKeyPropertyValue = newValue;
// now do the comparison
bool update = !(IsEqual(_currentGroupingKeyPropertyValue, oldValue) ||
IsEqual(oldValue, _currentGroupingKeyPropertyValue));
if (update && _label == null)
{
_groupingKeyDisplayName = results[0].ResolvedExpression.ToString();
}
return update;
}
// we had no matches or we could not get the value:
// NOTICE: we need to do this to avoid starting a new group every time
// there is a failure to read the grouping property.
// For example, for AD, there are objects that throw when trying
// to read the "distinguishedName" property (used by the brokered property "ParentPath)
return false;
}
private static bool IsEqual(object first, object second)
{
if (LanguagePrimitives.TryCompare(first, second, true, CultureInfo.CurrentCulture, out int result))
{
return result == 0;
}
// Note that this will occur if the objects do not support
// IComparable. We fall back to comparing as strings.
// being here means the first object doesn't support ICompare
// or an Exception was raised win Compare
string firstString = PSObject.AsPSObject(first).ToString();
string secondString = PSObject.AsPSObject(second).ToString();
return string.Equals(firstString, secondString, StringComparison.CurrentCultureIgnoreCase);
}
/// <summary>
/// Value of the display label passed in.
/// </summary>
private string _label = null;
/// <summary>
/// Value of the current active grouping key.
/// </summary>
private string _groupingKeyDisplayName = null;
/// <summary>
/// Name of the current grouping key.
/// </summary>
private PSPropertyExpression _groupingKeyExpression = null;
/// <summary>
/// The current value of the grouping key.
/// </summary>
private object _currentGroupingKeyPropertyValue = AutomationNull.Value;
}
}
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