From fa6a24ea308cb40bf4d650622430abd9b3db2623 Mon Sep 17 00:00:00 2001
From: Codex CLI <codex@example.com>
Date: Wed, 27 Aug 2025 03:27:26 -0500
Subject: [PATCH] Bindings: fix command lookup in DataTemplates by scoping
 Button.DataContext to root VM and using Tag to preserve item context; set
 CommandParameter via Tag.

---
 src/AdvancedCalculator/Views/MainView.axaml | 66 +++++++++++----------
 1 file changed, 36 insertions(+), 30 deletions(-)

diff --git a/src/AdvancedCalculator/Views/MainView.axaml b/src/AdvancedCalculator/Views/MainView.axaml
index 981363e..4f4bfdf 100644
--- a/src/AdvancedCalculator/Views/MainView.axaml
+++ b/src/AdvancedCalculator/Views/MainView.axaml
@@ -36,13 +36,16 @@
                    AutomationProperties.Name="Variables list">
             <ListBox.ItemTemplate>
               <DataTemplate x:DataType="m:VariableItem">
-                <Button Command="{Binding $parent[UserControl].DataContext.InsertVariableCommand}"
-                        CommandParameter="{Binding VariableName}"
-                        Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
-                        AutomationProperties.Name="Insert variable">
-                  <Grid ColumnDefinitions="Auto,*,Auto">
-                <TextBlock Grid.Column="0" FontFamily="{StaticResource MDI}"
-                           FontSize="{DynamicResource IconSizeM}" Text="{Binding Icon}" VerticalAlignment="Center" Margin="0,0,8,0" />
+                <Button Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
+                        AutomationProperties.Name="Insert variable"
+                        Tag="{Binding}"
+                        DataContext="{Binding $parent[UserControl].DataContext}"
+                        Command="{Binding InsertVariableCommand}"
+                        CommandParameter="{Binding Tag.VariableName, RelativeSource={RelativeSource Self}}">
+                  <Grid ColumnDefinitions="Auto,*,Auto"
+                        DataContext="{Binding Tag, RelativeSource={RelativeSource AncestorType=Button}}">
+                    <TextBlock Grid.Column="0" FontFamily="{StaticResource MDI}"
+                               FontSize="{DynamicResource IconSizeM}" Text="{Binding Icon}" VerticalAlignment="Center" Margin="0,0,8,0" />
                     <TextBlock Grid.Column="1" Text="{Binding VariableName}" FontWeight="Bold" VerticalAlignment="Center" />
                     <StackPanel Grid.Column="2" Spacing="6" VerticalAlignment="Center">
                       <TextBlock Text="{Binding Value}" />
@@ -65,30 +68,33 @@
                  ItemsSource="{x:Static m:FunctionDefinitionItem.DefinedFunctions}"
                  AutomationProperties.Name="Functions list">
           <ListBox.ItemTemplate>
-            <DataTemplate x:DataType="m:FunctionDefinitionItem">
-              <Button Command="{Binding $parent[UserControl].DataContext.InsertFunctionCommand}"
-                      CommandParameter="{Binding FunctionName}"
-                      Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
-                      AutomationProperties.Name="Insert function">
-                <StackPanel Spacing="8">
-                  <StackPanel Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
-                    <TextBlock FontFamily="{StaticResource MDI}" Text="{Binding Icon}" />
-                    <TextBlock Text="{Binding FunctionName}" FontWeight="Bold" />
+              <DataTemplate x:DataType="m:FunctionDefinitionItem">
+                <Button Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
+                        AutomationProperties.Name="Insert function"
+                        Tag="{Binding}"
+                        DataContext="{Binding $parent[UserControl].DataContext}"
+                        Command="{Binding InsertFunctionCommand}"
+                        CommandParameter="{Binding Tag.FunctionName, RelativeSource={RelativeSource Self}}">
+                  <StackPanel Spacing="8"
+                              DataContext="{Binding Tag, RelativeSource={RelativeSource AncestorType=Button}}">
+                    <StackPanel Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
+                      <TextBlock FontFamily="{StaticResource MDI}" Text="{Binding Icon}" />
+                      <TextBlock Text="{Binding FunctionName}" FontWeight="Bold" />
+                    </StackPanel>
+                    <TextBlock Text="{Binding FunctionDescription}" FontStyle="Italic" TextWrapping="Wrap" />
+                    <ItemsControl ItemsSource="{Binding FunctionArguments}">
+                      <ItemsControl.ItemTemplate>
+                        <DataTemplate>
+                          <StackPanel>
+                            <TextBlock Text="{Binding Key}" />
+                            <TextBlock Text="{Binding Value}" FontStyle="Italic" Margin="8,0,0,0" />
+                          </StackPanel>
+                        </DataTemplate>
+                      </ItemsControl.ItemTemplate>
+                    </ItemsControl>
                   </StackPanel>
-                  <TextBlock Text="{Binding FunctionDescription}" FontStyle="Italic" TextWrapping="Wrap" />
-                  <ItemsControl ItemsSource="{Binding FunctionArguments}">
-                    <ItemsControl.ItemTemplate>
-                      <DataTemplate>
-                        <StackPanel>
-                          <TextBlock Text="{Binding Key}" />
-                          <TextBlock Text="{Binding Value}" FontStyle="Italic" Margin="8,0,0,0" />
-                        </StackPanel>
-                      </DataTemplate>
-                    </ItemsControl.ItemTemplate>
-                  </ItemsControl>
-                </StackPanel>
-              </Button>
-            </DataTemplate>
+                </Button>
+              </DataTemplate>
           </ListBox.ItemTemplate>
         </ListBox>
       </Grid>