feat(xbind): Add pathless casting support

jeromelaban · Sep 28, 2022 · 21f12bc · 21f12bc
1 parent 2b2736d
commit 21f12bc
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Showing 8 changed files with 198 additions and 5 deletions.
diff --git a/doc/articles/features/windows-ui-xaml-xbind.md b/doc/articles/features/windows-ui-xaml-xbind.md
@@ -87,6 +87,28 @@ Uno supports the [`x:Bind`](https://docs.microsoft.com/en-us/windows/uwp/xaml-pl
   <TextBox FontFamily="{x:Bind (FontFamily)MyComboBox.SelectedValue}" />
   ```
 
+- [Pathless casting](https://learn.microsoft.com/en-us/windows/uwp/xaml-platform/x-bind-markup-extension#pathless-casting)
+  ```xml
+  <Page
+    x:Class="AppSample.MainPage"
+    ...
+    xmlns:local="using:AppSample">
+
+    <Grid>
+        <ListView ItemsSource="{x:Bind Songs}">
+            <ListView.ItemTemplate>
+                <DataTemplate x:DataType="local:SongItem">
+                    <TextBlock
+                        Margin="12"
+                        FontSize="40"
+                        Text="{x:Bind local:MainPage.GenerateSongTitle((local:SongItem))}" />
+                </DataTemplate>
+            </ListView.ItemTemplate>
+        </ListView>
+    </Grid>
+  </Page>
+  ```
+
 - `x:Load` binding
   ```xml
   <TextBox x:Load="{x:Bind IsMyControlVisible}" />

diff --git a/src/SourceGenerators/Uno.UI.SourceGenerators.Tests.Shared/Given_XBindRewriter.cs b/src/SourceGenerators/Uno.UI.SourceGenerators.Tests.Shared/Given_XBindRewriter.cs
@@ -30,6 +30,11 @@ public class Given_XBindRewriter
 		[DataRow("ctx", "(FontFamily)a.Value", "(FontFamily)ctx.a.Value")]
 		[DataRow("ctx", "(global::System.Int32)a.Value", "(global::System.Int32)ctx.a.Value")]
 
+		// Pathless casting https://learn.microsoft.com/en-us/windows/uwp/xaml-platform/x-bind-markup-extension#pathless-casting
+		[DataRow("ctx", "MyFunction((global::System.String))", "ctx.MyFunction(((global::System.String)ctx))")]
+		[DataRow("ctx", "MyFunction2((global::System.String),(global::System.String))", "ctx.MyFunction2(((global::System.String)ctx),((global::System.String)ctx))")]
+		[DataRow("ctx", "(global::System.String)", "((global::System.String)ctx)")]
+
 		// Not supported https://github.com/unoplatform/uno/issues/5061
 		// [DataRow("ctx", "MyFunction((global::System.Int32)MyProperty)", "ctx.MyFunction((global::System.Int32)ctx.MyProperty)")]
 

diff --git a/src/SourceGenerators/Uno.UI.SourceGenerators/XamlGenerator/Utils/XBindExpressionParser.cs b/src/SourceGenerators/Uno.UI.SourceGenerators/XamlGenerator/Utils/XBindExpressionParser.cs
@@ -104,15 +104,27 @@ private string ContextBuilder
 				var e = base.VisitMemberAccessExpression(node);
 				var isValidParent = !Helpers.IsInsideMethod(node).result && !Helpers.IsInsideMemberAccessExpression(node).result;
 				var isParentMemberStatic = node.Expression is MemberAccessExpressionSyntax m && _isStaticMember(m.ToFullString());
+				var isPathLessCast = Helpers.IsPathLessCast(node);
 
 				if (e!= null && isValidParent && !_isStaticMember(node.Expression.ToFullString()) && !isParentMemberStatic)
 				{
-					var expression = e.ToFullString();
-					var contextBuilder = _isStaticMember(expression) ? "" : ContextBuilder;
-					var output = ParseCompilationUnit($"class __Temp {{ private Func<object> __prop => {contextBuilder}{expression}; }}");
+					if (isPathLessCast.result)
+					{
+						var expression = e.ToFullString();
+						var output = ParseCompilationUnit($"class __Temp {{ private Func<object> __prop => ({isPathLessCast.expression?.Expression}){_contextName}; }}");
 
-					var o2 = output.DescendantNodes().OfType<ArrowExpressionClauseSyntax>().First().Expression;
-					return o2;
+						var newSyntax = output.DescendantNodes().OfType<ArrowExpressionClauseSyntax>().First().Expression;
+						return newSyntax;
+					}
+					else
+					{
+						var expression = e.ToFullString();
+						var contextBuilder = _isStaticMember(expression) ? "" : ContextBuilder;
+						var output = ParseCompilationUnit($"class __Temp {{ private Func<object> __prop => {contextBuilder}{expression}; }}");
+
+						var newSyntax = output.DescendantNodes().OfType<ArrowExpressionClauseSyntax>().First().Expression;
+						return newSyntax;
+					}
 				}
 				else
 				{
@@ -259,6 +271,31 @@ internal static (bool result, CastExpressionSyntax? expression) IsInsideCast(Syn
 
 				return (false, null);
 			}
+
+			internal static (bool result, ParenthesizedExpressionSyntax? expression) IsPathLessCast(SyntaxNode node)
+			{
+				var currentNode = node.Parent;
+
+				do
+				{
+					if (currentNode is ArgumentSyntax arg
+						&& arg.Expression is ParenthesizedExpressionSyntax expressionSyntax)
+					{
+						return (true, expressionSyntax);
+					}
+
+					if (currentNode is ArrowExpressionClauseSyntax arrow
+						&& arrow.Expression is ParenthesizedExpressionSyntax expressionSyntax2)
+					{
+						return (true, expressionSyntax2);
+					}
+
+					currentNode = currentNode?.Parent;
+				}
+				while (currentNode != null);
+
+				return (false, null);
+			}
 		}
 	}
 }
diff --git a/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting.xaml b/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting.xaml
@@ -0,0 +1,17 @@
+<UserControl x:Class="Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls.xBind_PathLessCasting"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:local="using:Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls"
+	xmlns:xc="using:Windows.UI.Xaml.Controls"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    d:DesignHeight="300"
+    d:DesignWidth="400">
+
+    <Grid>
+		<TextBlock x:Name="tb1"
+				   x:FieldModifier="public"
+				   Tag="{x:Bind (xc:UserControl)}" />
+	</Grid>
+</UserControl>
diff --git a/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting.xaml.cs b/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting.xaml.cs
@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+// The User Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234236
+
+namespace Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls
+{
+	public sealed partial class xBind_PathLessCasting : UserControl
+	{
+		public xBind_PathLessCasting()
+		{
+			this.InitializeComponent();
+		}
+	}
+}
diff --git a/...Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting_Template.xaml b/...Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting_Template.xaml
@@ -0,0 +1,26 @@
+<UserControl x:Class="Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls.xBind_PathLessCasting_Template"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:local="using:Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    d:DesignHeight="300"
+    d:DesignWidth="400">
+
+
+	<Grid>
+		<ContentControl x:Name="root"
+						x:FieldModifier="public">
+			<ContentControl.ContentTemplate>
+				<DataTemplate x:DataType="local:xBind_PathLessCasting_Template_Model">
+					<Grid>
+						<TextBlock x:Name="tb1"
+								   x:FieldModifier="public"
+								   Tag="{x:Bind (local:xBind_PathLessCasting_Template_Model)}" />
+					</Grid>
+				</DataTemplate>
+			</ContentControl.ContentTemplate>
+		</ContentControl>
+	</Grid>
+</UserControl>
diff --git a/....UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting_Template.xaml.cs b/....UI.Tests/Windows_UI_Xaml_Data/xBindTests/Controls/xBind_PathLessCasting_Template.xaml.cs
@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+// The User Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234236
+
+namespace Uno.UI.Tests.Windows_UI_Xaml_Data.xBindTests.Controls
+{
+	public sealed partial class xBind_PathLessCasting_Template : UserControl
+	{
+		public xBind_PathLessCasting_Template()
+		{
+			this.InitializeComponent();
+		}
+	}
+
+	public class xBind_PathLessCasting_Template_Model
+	{
+
+	}
+}
diff --git a/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Given_xBind_Binding.cs b/src/Uno.UI.Tests/Windows_UI_Xaml_Data/xBindTests/Given_xBind_Binding.cs
@@ -1264,6 +1264,31 @@ public async Task When_NullableRecordStruct()
 			Assert.AreEqual("42", SUT.tb1.Text);
 		}
 
+		[TestMethod]
+		public async Task When_PathLessCasting()
+		{
+			var SUT = new xBind_PathLessCasting();
+
+			SUT.ForceLoaded();
+
+			Assert.AreEqual(SUT, SUT.tb1.Tag);
+		}
+
+		[TestMethod]
+		public async Task When_PathLessCasting_Template()
+		{
+			var SUT = new xBind_PathLessCasting_Template();
+
+			SUT.ForceLoaded();
+
+			var rootData = new xBind_PathLessCasting_Template_Model();
+			SUT.root.Content = rootData;
+
+			var myObject = SUT.FindName("tb1") as TextBlock;
+
+			Assert.AreEqual(rootData, myObject.Tag);
+		}
+
 		private async Task AssertIsNullAsync<T>(Func<T> getter, TimeSpan? timeout = null) where T:class
 		{
 			timeout ??= TimeSpan.FromSeconds(1);