uno-toolkit-ancestor-binding

name	uno-toolkit-ancestor-binding
description	Use AncestorBinding and ItemsControlBinding markup extensions for relative binding from within DataTemplates. Access parent DataContext.
when_to_use	Use when binding inside a `DataTemplate` needs to reach the outer `DataContext`, the page's ViewModel, or an ancestor `ItemsControl` — the Uno equivalent of WPF's `RelativeSource FindAncestor`. `ItemsControlBinding` exposes the parent ItemsControl's own `DataContext` from within its item template.
metadata	{"author":"uno-platform","version":"2.4","category":"toolkit"}

Uno Toolkit AncestorBinding — Agent Skill

Workflow

Docs lookup: call uno_platform_docs_search(...) first, then uno_platform_docs_fetch(sourcePath="…") using the sourcePath field from a result (a relative .md path; add the result's anchor for a section). Never pass a URL, a .html link, or a hand-built path.

Step 1: Fetch the AncestorBinding Documentation

uno_platform_docs_search("Uno Toolkit AncestorBinding ItemsControlBinding relative binding DataTemplate ancestor")

Primary documentation page:

• AncestorBinding & ItemsControlBinding: external/uno.toolkit.ui/doc/helpers/ancestor-itemscontrol-binding.md

Fetch the page:

uno_platform_docs_fetch(sourcePath="external/uno.toolkit.ui/doc/helpers/ancestor-itemscontrol-binding.md")

Key Principles (Stable)

• {utu:AncestorBinding AncestorType=MyControl, Path=DataContext.MyProperty} — binds to an ancestor's DataContext
• {utu:ItemsControlBinding Path=DataContext.MyCommand} — shorthand for binding to the parent ItemsControl's DataContext
• Similar to WPF's {RelativeSource Mode=FindAncestor, AncestorType=...}
• Essential for commands in DataTemplates that need to call the page's ViewModel
• XAML namespace: xmlns:utu="using:Uno.Toolkit.UI"

Related Skills

• [[uno-toolkit-command-extensions]] — Commands in templates