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Merge pull request #1 from Yeah69/master
Extension of the lambda-converters to support DataTemplateSelectors and ValidationRules
2 parents be0a05a + f741a5c commit 1fab97a

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‎README.md

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@@ -36,6 +36,84 @@ You're done! Just reference the converters with the `x:Static` expressions from
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:bulb: *ReSharper users*: use the Extension Manager to install the external annotations for the library.
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## Lambda DataTemplateSelectors
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The library also allows to create `DataTemplateSelector` objects in the same convenient way as Converters. In order to define a Selector simply write a static field (or property) similar to this snippet:
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```csharp
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internal static class TemplateSelector
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{
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public static DataTemplateSelector AlternatingText =
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LambdaConverters.TemplateSelector.Create<int>(
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e => e.Item % 2 == 0
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? (DataTemplate) ((FrameworkElement) e.Container)?.FindResource("BlackWhite")
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: (DataTemplate) ((FrameworkElement) e.Container)?.FindResource("WhiteBlack"));
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}
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```
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Use your Lambda DataTemplateSelectors by referencing it with the `x:Static` markup extention:
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```xml
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<UserControl.Resources>
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<DataTemplate x:Key="BlackWhite">
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<TextBlock Text="{Binding}"
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Foreground="Black"
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Background="White" />
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</DataTemplate>
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<DataTemplate x:Key="WhiteBlack">
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<TextBlock Text="{Binding}"
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Foreground="White"
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Background="Black" />
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</DataTemplate>
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</UserControl.Resources>
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<DockPanel>
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<ListBox ItemsSource="{Binding IntNumbers}"
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ItemTemplateSelector="{x:Static s:TemplateSelector.AlternatingText}">
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</ListBox>
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</DockPanel>
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```
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Tada! All even numbers from `IntNumbers` are displayed with black font and white background and the odd numbers get the inverse font and background colors.
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### Features
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- *strongly-typed* Selectors
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- resource declaration not needed, just use the `x:Static` expressions
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- separate class for each selector not needed anymore
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- full support for the remaining parameter `container`. For example, if you need to grab a `DataTemplate` from where the selector is use (see the example above).
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## Lambda ValidationRules
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Furthermore, you'll get Lambda ValidationRules on top. By now you know "the drill". First, define a `ValidationRule`object like this:
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```csharp
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public static class Rule
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{
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public static ValidationRule IsNumericString =
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LambdaConverters.Validator.Create<string>(
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e => e.Value.ToCharArray().All(char.IsDigit)
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? ValidationResult.ValidResult
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: new ValidationResult(false, "Text has non-digit characters!"));
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}
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```
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And then reference your new rule in vour `View`:
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```xml
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<TextBox>
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<TextBox.Text>
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<Binding Path="Text" UpdateSourceTrigger="PropertyChanged">
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<Binding.ValidationRules>
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<x:Static Member="r:Rule.IsNumericString"/>
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</Binding.ValidationRules>
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</Binding>
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</TextBox.Text>
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</TextBox>
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```
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Now, you made sure that only strings which consists of digits are passed to your `ViewModel`.
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### Features
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- *strongly-typed* rules
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- resource declaration not needed, just use the `x:Static` expressions
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- separate class for each rule not needed anymore
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- full support for the remaining parameter `culture`
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## Installation
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Use the NuGet package manager to install the package.
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‎Sources/LambdaConverters.Wpf/EventSource.cs

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@@ -13,6 +13,8 @@ internal sealed class EventSource : System.Diagnostics.Tracing.EventSource
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public static class Keywords
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{
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public const EventKeywords Converters = (EventKeywords)0x4;
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public const EventKeywords Selectors = (EventKeywords)0x8;
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public const EventKeywords Rules = (EventKeywords)0x10;
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}
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[NotNull]
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memberName,
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sourceFilePath,
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sourceLineNumber);
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/// <summary>
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/// The {0} is null, conversion result is a value according to the specified error strategy ({1}).
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/// </summary>
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[Conditional("TRACE")]
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[Event(
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22,
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Version = 0,
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Message = "The {0} is null, conversion result is a value according to the specified error strategy ({1}).",
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Level = EventLevel.Warning,
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Keywords = Keywords.Selectors,
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Opcode = EventOpcode.Info,
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Channel = EventChannel.Operational
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)]
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public void MissingSelectTemplateFunction(
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string callback,
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string errorStrategy,
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[CallerMemberName] string memberName = null,
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[CallerFilePath] string sourceFilePath = null,
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[CallerLineNumber] int sourceLineNumber = 0)
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=>
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WriteEvent(
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22,
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callback,
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errorStrategy,
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memberName,
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sourceFilePath,
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sourceLineNumber);
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/// <summary>
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/// The value ({0}) cannot be cast to the specified input type ({1}), conversion result is a value according to the specified error strategy ({2}).
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/// </summary>
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[Conditional("TRACE")]
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[Event(
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23,
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Version = 0,
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Message = "The value ({0}) cannot be cast to the specified input type ({1}), conversion result is a value according to the specified error strategy ({2}).",
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Level = EventLevel.Warning,
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Keywords = Keywords.Selectors,
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Opcode = EventOpcode.Info,
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Channel = EventChannel.Operational
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)]
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public void UnableToCastToItemType(
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string itemType,
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string inputType,
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string errorStrategy,
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[CallerMemberName] string memberName = null,
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[CallerFilePath] string sourceFilePath = null,
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[CallerLineNumber] int sourceLineNumber = 0)
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=>
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WriteEvent(
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23,
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itemType,
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inputType,
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errorStrategy,
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memberName,
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sourceFilePath,
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sourceLineNumber);
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/// <summary>
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/// The {0} is null, conversion result is a value according to the specified error strategy ({1}).
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/// </summary>
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[Conditional("TRACE")]
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[Event(
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24,
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Version = 0,
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Message = "The {0} is null, conversion result is a value according to the specified error strategy ({1}).",
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Level = EventLevel.Warning,
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Keywords = Keywords.Rules,
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Opcode = EventOpcode.Info,
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Channel = EventChannel.Operational
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)]
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public void MissingRuleFunction(
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string callback,
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string errorStrategy,
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[CallerMemberName] string memberName = null,
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[CallerFilePath] string sourceFilePath = null,
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[CallerLineNumber] int sourceLineNumber = 0)
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=>
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WriteEvent(
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24,
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callback,
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errorStrategy,
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memberName,
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sourceFilePath,
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sourceLineNumber);
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/// <summary>
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/// The value ({0}) cannot be cast to the specified input type ({1}), conversion result is a value according to the specified error strategy ({2}).
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/// </summary>
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[Conditional("TRACE")]
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[Event(
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25,
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Version = 0,
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Message = "The value ({0}) cannot be cast to the specified input type ({1}), conversion result is a value according to the specified error strategy ({2}).",
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Level = EventLevel.Warning,
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Keywords = Keywords.Rules,
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Opcode = EventOpcode.Info,
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Channel = EventChannel.Operational
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)]
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public void UnableToCastToRuleInputType(
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string itemType,
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string inputType,
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string errorStrategy,
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[CallerMemberName] string memberName = null,
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[CallerFilePath] string sourceFilePath = null,
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[CallerLineNumber] int sourceLineNumber = 0)
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=>
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WriteEvent(
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25,
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itemType,
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inputType,
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errorStrategy,
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memberName,
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sourceFilePath,
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sourceLineNumber);
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}
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}

‎Sources/LambdaConverters.Wpf/LambdaConverters.Wpf.csproj

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</ItemGroup>
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<ItemGroup>
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<Compile Include="Converter.cs" />
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<Compile Include="RuleErrorStrategy.cs" />
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<Compile Include="SelectorErrorStrategy.cs" />
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<Compile Include="ConverterErrorStrategy.cs" />
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<Compile Include="EventSource.cs" />
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<Compile Include="MultiValueConverter.cs" />
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<Compile Include="MultiValueConverterArgs[T].cs" />
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<Compile Include="MultiValueConverterArgs[T].IEquatable[MultiValueConverterArgs[T]].cs" />
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<Compile Include="Properties\AssemblyInfo.cs" />
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<Compile Include="Validator.cs" />
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<Compile Include="TemplateSelector.cs" />
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<Compile Include="ValueConverter.cs" />
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<Compile Include="ValidationRuleArgs[T].cs" />
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<Compile Include="ValueConverterArgs[T,P].cs" />
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<Compile Include="ValueConverterArgs[T,P].IEquatable[ValueConverterArgs[T,P]].cs" />
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<Compile Include="TemplateSelectorArgs[T].cs" />
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<Compile Include="ValueConverterArgs[T].cs" />
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<Compile Include="TemplateSelectorArgs[T].IEquatable[TemplateSelectorArgs[T]].cs" />
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<Compile Include="ValidationRuleArgs[T].IEquatable[ValidationRuleArgs[T]].cs" />
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<Compile Include="ValueConverterArgs[T].IEquatable[ValueConverterArgs[T]].cs" />
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</ItemGroup>
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<ItemGroup>

‎Sources/LambdaConverters.Wpf/Properties/AssemblyInfo.cs

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[assembly: AssemblyConfiguration("")]
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[assembly: AssemblyCompany("")]
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[assembly: AssemblyProduct("LambdaConverters")]
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[assembly: AssemblyCopyright("© 2016 Michael Damatov.")]
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[assembly: AssemblyCopyright("© 2017 Michael Damatov, Dimitri Enns.")]
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[assembly: AssemblyTrademark("")]
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[assembly: AssemblyCulture("")]
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‎Sources/LambdaConverters.Wpf/RuleErrorStrategy.cs

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using System.Windows.Controls;
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namespace LambdaConverters
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{
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/// <summary>
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/// Defines the validation rule error strategy.
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/// </summary>
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public enum RuleErrorStrategy
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{
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/// <summary>
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/// Null is returned.
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/// </summary>
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ReturnNull,
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/// <summary>
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/// An invalid validation result is returned.
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/// </summary>
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ReturnInvalid,
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/// <summary>
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/// A valid validation result is returned.
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/// </summary>
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ReturnValid
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}
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}

‎Sources/LambdaConverters.Wpf/SelectorErrorStrategy.cs

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namespace LambdaConverters
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{
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/// <summary>
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/// Defines the selector error strategy.
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/// </summary>
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public enum SelectorErrorStrategy
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{
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/// <summary>
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/// Null is returned.
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/// </summary>
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ReturnNull,
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/// <summary>
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/// A new and empty data template is returned.
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/// </summary>
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ReturnNewEmptyDataTemplate
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}
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}

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