From ad8e178484741e76d06f77a5605548afde0c93d2 Mon Sep 17 00:00:00 2001
From: Codex CLI <codex@example.com>
Date: Thu, 28 Aug 2025 03:50:27 -0500
Subject: [PATCH] Fix function list DataTemplate binding: keep item DataContext
 (FunctionDefinitionItem) and bind Button.Command to parent MainViewModel via
 ancestor binding. Pass item as CommandParameter. Prevents binding errors for
 FunctionName/FunctionDescription.

---
 src/AdvancedCalculator/Views/MainView.axaml | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/AdvancedCalculator/Views/MainView.axaml b/src/AdvancedCalculator/Views/MainView.axaml
index 3d6cdd0..b4f9990 100644
--- a/src/AdvancedCalculator/Views/MainView.axaml
+++ b/src/AdvancedCalculator/Views/MainView.axaml
@@ -155,10 +155,9 @@
                                                 <ListBox ItemsSource="{Binding Functions}" BorderThickness="0" SelectedIndex="-1">
                                                     <ListBox.ItemTemplate>
                                                         <DataTemplate x:DataType="m:FunctionDefinitionItem">
-                                                            <Button x:DataType="vm:MainViewModel"
-                                                                    DataContext="{Binding #Root.DataContext}"
-                                                                    Command="{Binding InsertFunctionCommand}"
-                                                                    CommandParameter="{Binding $parent[ListBoxItem].DataContext}"
+                                                            <Button
+                                                                    Command="{Binding $parent[ListBox].DataContext.InsertFunctionCommand}"
+                                                                    CommandParameter="{Binding}"
                                                                     Background="Transparent" BorderThickness="0" Padding="8" MinHeight="36"
                                                                     AutomationProperties.Name="Insert function">
                                                                 <Grid ColumnDefinitions="*,Auto">