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Pull request overview
This PR fixes a crash in the XAML Source Generator (XSG) when Style.Setter targets a partial property decorated with the [BindableProperty] attribute from CommunityToolkit.MAUI. The issue occurs because source generators run in isolation - when XSG processes the XAML, it cannot see the BindableProperty field generated by another source generator running in parallel.
Changes:
- Made
GetBindablePropertyreturn nullable and updated all call sites to handle null gracefully - Added heuristic detection logic to identify properties with
[BindableProperty]attributes even when the generated field is not visible - Added fallback logic in
SetterValueProviderto construct BindableProperty references from type and property name - Comprehensive test coverage for both source generator and runtime scenarios
Reviewed changes
Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| NodeSGExtensions.cs | Changed GetBindableProperty return type from IFieldSymbol to IFieldSymbol? to allow null returns |
| BindablePropertyConverter.cs | Added null check and fallback to "default" when BindableProperty is not found |
| SetterValueProvider.cs | Added heuristic fallback logic to detect [BindableProperty] attributes and construct BP references manually |
| ITypeSymbolExtensions.Maui.cs (not shown) | Added HasBindablePropertyHeuristic method to detect properties with recognized bindable property attributes |
| Maui33835.xaml | XAML test file with Style Setter targeting property with [BindableProperty] attribute |
| Maui33835.xaml.cs | Runtime test verifying Style Setter works correctly with all inflators |
| PartialPropertyInStyleSetterTests.cs | Source generator unit tests covering scenarios with/without visible BindableProperty field |
src/Controls/tests/SourceGen.UnitTests/InitializeComponent/PartialPropertyInStyleSetterTests.cs
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StephaneDelcroix
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Feb 11, 2026
…erated BindableProperty Fixes #33835 When a Style Setter uses a markup extension (e.g., {StaticResource}) on a property with [BindableProperty] attribute from CommunityToolkit.MAUI, the XSG couldn't find the BindableProperty field because it's generated by another source generator running in parallel. The markup extension case wasn't handled by the existing fix (#33562) because SetterValueProvider.CanProvideValue returns false for markup extensions, causing the Setter to go through the standard processing path via BindablePropertyConverter, which called GetBindableProperty() and crashed on the null result. Fix: - Make GetBindableProperty(ValueNode) return IFieldSymbol? (nullable) instead of throwing when BP field is not found - Add heuristic fallback in BindablePropertyConverter to detect [BindableProperty] attributes on properties, matching the approach already used in SetterValueProvider - Add tests for the markup extension scenario
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/azp run maui-pr-devicetests,maui-pr-uitests |
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Azure Pipelines successfully started running 2 pipeline(s). |
This was referenced Feb 11, 2026
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It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!
Description
Fixes #33835
This PR fixes a remaining gap in the XSG handling of source-generated bindable properties (from CommunityToolkit.MAUI
[BindableProperty]attribute) — specifically when markup extensions like{StaticResource}are used in Style Setters.Background
PR #33562 fixed Style Setters with simple literal values on source-generated bindable properties. However, when the Setter value uses a markup extension (e.g.,
{StaticResource TestColor}), a different code path is taken:SetterValueProvider.CanProvideValue()returnsfalsefor markup extensionsBindablePropertyConverterBindablePropertyConvertercallsGetBindableProperty()which returns null (field not visible to XSG)MAUIG1001: The method or operation is not implementedChanges
NodeSGExtensions.GetBindableProperty(ValueNode): Changed return type toIFieldSymbol?(nullable) — returns null instead of throwing when the bindable property field is not foundBindablePropertyConverter: Added heuristic fallback to detect[BindableProperty]attributes and construct the BP reference, matching the approach already used inSetterValueProviderReview Note
The Copilot reviewer comment about missing
TestColorresource was incorrect — the resource IS defined in both tests that reference it. The 3rd test uses a simple string value and correctly does not define it.