Fix compiled binding with TemplatedParent relative source

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs

@@ -45,10 +45,10 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                 new AvaloniaXamlIlReorderClassesPropertiesTransformer()
             );
 
-            InsertBefore<ContentConvertTransformer>(                
-                new AvaloniaXamlIlBindingPathParser(),
+            InsertBefore<ContentConvertTransformer>(
                 new AvaloniaXamlIlSelectorTransformer(),
-                new AvaloniaXamlIlControlTemplateTargetTypeMetadataTransformer(),
+                new AvaloniaXamlIlControlTemplateTargetTypeMetadataTransformer(),                 
+                new AvaloniaXamlIlBindingPathParser(),
                 new AvaloniaXamlIlPropertyPathTransformer(),
                 new AvaloniaXamlIlSetterTransformer(),
                 new AvaloniaXamlIlConstructorServiceProviderTransformer(),

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathParser.cs

@@ -121,11 +121,14 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 {
                     throw new XamlParseException("Only one of ElementName, Source, or RelativeSource specified as a binding source. Only one property is allowed.", binding);
                 }
-
-                var mode = relativeSourceObject.Children
+                
+                var modeProperty = relativeSourceObject.Children
                     .OfType<XamlAstXamlPropertyValueNode>()
-                    .FirstOrDefault(x => x.Property.GetClrProperty().Name == "Mode")
-                    ?.Values[0] is XamlAstTextNode modeAssignedValue ? modeAssignedValue.Text : null;
+                    .FirstOrDefault(x => x.Property.GetClrProperty().Name == "Mode")?
+                    .Values.FirstOrDefault() as XamlAstTextNode
+                    ?? relativeSourceObject.Arguments.OfType<XamlAstTextNode>().FirstOrDefault();
+                
+                var mode = modeProperty?.Text;
                 if (relativeSourceObject.Arguments.Count == 0 && mode == null)
                 {
                     mode = "FindAncestor";
@@ -212,16 +215,20 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 }
                 else if (mode == "TemplatedParent")
                 {
-                    var parentType = context.ParentNodes().OfType<AvaloniaXamlIlTargetTypeMetadataNode>()
+                    var contentTemplateNode = context.ParentNodes().OfType<AvaloniaXamlIlTargetTypeMetadataNode>()
                         .FirstOrDefault(x =>
-                            x.ScopeType == AvaloniaXamlIlTargetTypeMetadataNode.ScopeTypes.ControlTemplate)
-                        ?.TargetType.GetClrType();
-
-                    if (parentType is null)
+                            x.ScopeType == AvaloniaXamlIlTargetTypeMetadataNode.ScopeTypes.ControlTemplate);
+                    if (contentTemplateNode is null)
                     {
                         throw new XamlParseException("A binding with a TemplatedParent RelativeSource has to be in a ControlTemplate.", binding);
                     }
 
+                    var parentType = contentTemplateNode.TargetType.GetClrType();
+                    if (parentType is null)
+                    {
+                        throw new XamlParseException("TargetType has to be set on ControlTemplate.", binding);
+                    } 
+
                     convertedNode = new TemplatedParentBindingExpressionNode { Type = parentType };
                 }
                 else

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlBindingPathHelper.cs

@@ -244,6 +244,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                     case TemplatedParentBindingExpressionNode templatedParent:
                         var templatedParentField = context.GetAvaloniaTypes().StyledElement.GetAllFields()
                             .FirstOrDefault(f => f.IsStatic && f.IsPublic && f.Name == "TemplatedParentProperty");
+                        nodes.Add(new SelfPathElementNode(selfType));
                         nodes.Add(new XamlIlAvaloniaPropertyPropertyPathElementNode(
                             templatedParentField,
                             templatedParent.Type));

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs

@@ -3,8 +3,8 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.Globalization;
+using System.Linq;
 using System.Reactive.Subjects;
-using System.Text;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.Controls.Presenters;
@@ -17,8 +17,6 @@ using Avalonia.Markup.Xaml.Templates;
 using Avalonia.Media;
 using Avalonia.Metadata;
 using Avalonia.UnitTests;
-using JetBrains.Annotations;
-using XamlX;
 using Xunit;
 
 namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
@@ -676,6 +674,32 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             }
         }
 
+        [Fact]
+        public void ResolvesRelativeSourceBindingFromTemplate()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<ContentControl xmlns='https://github.com/avaloniaui'
+                Content='Hello'>
+    <ContentControl.Styles>
+        <Style Selector='ContentControl'>
+            <Setter Property='Template'>
+                <ControlTemplate>
+                    <ContentPresenter Content='{CompiledBinding Content, RelativeSource={RelativeSource TemplatedParent}}' />
+                </ControlTemplate>
+            </Setter>
+        </Style>
+    </ContentControl.Styles>
+</ContentControl>";
+
+                var contentControl = AvaloniaRuntimeXamlLoader.Parse<ContentControl>(xaml);
+                contentControl.Measure(new Size(10, 10));
+                
+                var result = contentControl.GetTemplateChildren().OfType<ContentPresenter>().First();
+                Assert.Equal("Hello", result.Content);
+            }
+        }
         
         [Fact]
         public void ResolvesElementNameInTemplate()