XAML Internal Compiler Error - DataGrid CompiledBindings

[wsficke]

Version Info
Avalonia 11.0.10

Nature of Issue
Introducing a DataGrid column when CompiledBindings are set to true causes an XAML compilation error. It is very confusing.

Isolation of Issue
This has to do with DataGrid and compiled bindings (see workaround below)

Expected Behavior
Compiled bindings should work for DataGrid columns

XAML binding (error is coming from "{Binding ViewModel.CustomerId}")
Note: Customers implements IReadOnlyList<AsyncVirtualizingCollectionProxy<TViewModel>> where TViewModel is CustomerViewModel [which declares CustomerId, PhoneNumber, FirstName, LastName]

<DataGrid Name="DataGrid" Grid.Row="1" VerticalAlignment="Stretch" ItemsSource="{Binding Customers}">
	<DataGrid.Columns>
		<DataGridTextColumn IsReadOnly="True" Header="Code" Binding="{Binding ViewModel.CustomerId}" />
		<DataGridTextColumn IsReadOnly="True" Header="Phone" Binding="{Binding ViewModel.PhoneNumber}" />
		<DataGridTextColumn IsReadOnly="True" Header="First" Binding="{Binding ViewModel.FirstName}" />
		<DataGridTextColumn IsReadOnly="True" Header="Last" Binding="{Binding ViewModel.LastName}" />
	</DataGrid.Columns>
</DataGrid>

Output from Build

3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004: Internal compiler error while transforming node XamlX.Ast.XamlAstConstructableObjectNode:
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004: System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004:    at Mono.Collections.Generic.Collection`1.get_Item(Int32 index)
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004:    at XamlX.TypeSystem.CecilHelpers.TransformGeneric(TypeReference reference, TypeReference declaringType) in /_/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github/src/XamlX.IL.Cecil/CecilHelpers.cs:line 20
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004:    at XamlX.TypeSystem.CecilHelpers.TransformGeneric(TypeReference reference, TypeReference declaringType) in /_/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github/src/XamlX.IL.Cecil/CecilHelpers.cs:line 25
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004:    at XamlX.TypeSystem.CecilTypeSystem.CecilMethodBase.<.ctor>g__MakeRef|13_0(Boolean transform, <>c__DisplayClass13_0& )
3>...\Views/Customer/CustomerLookup2View.axaml(52,57,52,57): Avalonia error AVLN:0004:    at XamlX.TypeSystem.CecilTypeSystem.CecilMethodBase..ctor(CecilTypeSystem typeSystem, MethodReference method, TypeReference declaringType) in /_/src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github/src/XamlX.IL.Cecil/CecilMe... Line 52, position 57.

[wsficke]

Found workaround - use dynamic binding for DataGrid columns

		<DataGrid Name="DataGrid" Grid.Row="1" VerticalAlignment="Stretch" ItemsSource="{Binding Customers}">
			<DataGrid.Columns>
				<DataGridTextColumn x:CompileBindings="false" IsReadOnly="True" Header="Code" Binding="{Binding ViewModel.CustomerId}" />
				<DataGridTextColumn x:CompileBindings="false" IsReadOnly="True" Header="Phone" Binding="{Binding ViewModel.PhoneNumber}" />
				<DataGridTextColumn x:CompileBindings="false" IsReadOnly="True" Header="First" Binding="{Binding ViewModel.FirstName}" />
				<DataGridTextColumn x:CompileBindings="false" IsReadOnly="True" Header="Last" Binding="{Binding ViewModel.LastName}" />
			</DataGrid.Columns>
		</DataGrid>

[wsficke]

If there's an additional type annotation required in the XAML to get this to work, improved messaging around it would be a great resolution.

[maxkatz6]

Yes, compile error message should be more helpful.
I am not familiar with AsyncVirtualizingCollectionProxy type, so minimal sample project might be helpful here.

Normally, DataGrid columns should pick-up properties from ItemsSource collection children without any extra annotation.
You can, though, write something like Binding="{Binding ViewModel.CustomerId, DataType=ns:CollectionChildType}"

[wsficke]

AsyncVirtualizingCollectionProxy is just another view model, with a nullable property named ViewModel that gets background loaded. It is not integral to the issue. The bug happens with flat (non-path), non-nullable, and non-generic bindings too. It's specific to DataGrid columns AFAIK.