Improve Compiled Bindings + Context

docfx/articles/dock-content-guide.md

@@ -532,6 +532,25 @@ var document = new Document
 </DocumentTemplate>
 ```
 
+### Issue: Compiled binding errors for `Context.*`
+
+**Problem**: Build errors like "Unable to resolve property or method ... on type 'Document'" when using `{Binding Context.SomeProperty}`.
+
+**Cause**: `Document.Context` is typed `object?`, so compiled bindings cannot infer model properties from `Context`.
+
+**Solution**: Rebind a subtree to the model and set `x:DataType`, or cast in the binding path (or disable compiled bindings for that subtree).
+
+```xaml
+<DocumentTemplate>
+  <StackPanel x:DataType="Document">
+    <StackPanel DataContext="{Binding Context}"
+                x:DataType="vm:MyDocumentModel">
+      <TextBox Text="{Binding Content}"/>
+    </StackPanel>
+  </StackPanel>
+</DocumentTemplate>
+```
+
 ### Issue: Empty/Blank Document Tabs with DataTemplates
 
 **Problem**: Document tabs show up but content is empty when using ViewModel approach.

docfx/articles/dock-itemssource.md

@@ -177,6 +177,19 @@ public class DocumentModel
 </DocumentTemplate>
 ```
 
+> **Compiled bindings + Context**: When using compiled bindings, `Context` is `object?` on `Document`, so `{Binding Context.SomeProperty}` can fail to compile. Rebind a subtree to the model and set a concrete `x:DataType`, or cast in the binding path:
+>
+> ```xaml
+> <DocumentTemplate>
+>   <StackPanel x:DataType="Document">
+>     <StackPanel DataContext="{Binding Context}"
+>                 x:DataType="models:FileDocument">
+>       <TextBox Text="{Binding Content}"/>
+>     </StackPanel>
+>   </StackPanel>
+> </DocumentTemplate>
+> ```
+
 ## Common Use Cases
 
 ### File Editor

samples/DockXamlSample/ItemsSourceExample.axaml

@@ -1,5 +1,6 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:dock="using:Dock.Model.Avalonia.Controls"
              xmlns:local="using:DockXamlSample"
              x:Class="DockXamlSample.ItemsSourceExample">
 
@@ -38,8 +39,15 @@
               <StackPanel Margin="10" x:DataType="Document">
                 <TextBlock Text="Document Title:" FontWeight="Bold"/>
                 <TextBox Text="{Binding Title}" Margin="0,0,0,10"/>
-                <TextBlock Text="Context Data:" FontWeight="Bold"/>
-                <TextBlock Text="{Binding Context}" TextWrapping="Wrap" Height="100" Background="LightGray" Padding="5"/>
+                <TextBlock Text="Model Content:" FontWeight="Bold"/>
+                <StackPanel DataContext="{Binding Context}">
+                  <StackPanel x:DataType="local:MyDocumentModel">
+                    <TextBlock Text="{Binding Content}" TextWrapping="Wrap" Height="80" Background="LightGray" Padding="5"/>
+                    <TextBlock Text="Editable Content:" FontWeight="Bold" Margin="0,10,0,0"/>
+                    <TextBox Text="{Binding EditableContent}" AcceptsReturn="True" Height="80"/>
+                    <TextBlock Text="{Binding Status}" Opacity="0.7" Margin="0,8,0,0"/>
+                  </StackPanel>
+                </StackPanel>
               </StackPanel>
             </DocumentTemplate>
           </DocumentDock.DocumentTemplate>
@@ -52,4 +60,4 @@
 
   </Grid>
 
-</UserControl> 
+</UserControl> 

src/Dock.Model.Avalonia/Controls/Document.cs

@@ -98,6 +98,7 @@ public int MdiZIndex
     /// <summary>
     /// 
     /// </summary>
+    [DataType]
     [IgnoreDataMember]
     [JsonIgnore]
     public Type? DataType { get; set; }

src/Dock.Model.Avalonia/Controls/DocumentTemplate.cs

@@ -37,6 +37,7 @@ public DocumentTemplate()
     /// <summary>
     /// 
     /// </summary>
+    [DataType]
     [IgnoreDataMember]
     [JsonIgnore]
     public Type? DataType { get; set; }

src/Dock.Model.Avalonia/Controls/Tool.cs

@@ -100,6 +100,7 @@ public int MdiZIndex
     /// <summary>
     /// 
     /// </summary>
+    [DataType]
     [IgnoreDataMember]
     [JsonIgnore]
     public Type? DataType { get; set; }