diff --git a/src/Avalonia.Controls/Templates/DataTemplates.cs b/src/Avalonia.Controls/Templates/DataTemplates.cs index f203539536..d4eeda7908 100644 --- a/src/Avalonia.Controls/Templates/DataTemplates.cs +++ b/src/Avalonia.Controls/Templates/DataTemplates.cs @@ -1,3 +1,4 @@ +using System; using Avalonia.Collections; namespace Avalonia.Controls.Templates @@ -13,6 +14,22 @@ namespace Avalonia.Controls.Templates public DataTemplates() { ResetBehavior = ResetBehavior.Remove; + + Validate += ValidateDataTemplate; + } + + private static void ValidateDataTemplate(IDataTemplate template) + { + var valid = template switch + { + ITypedDataTemplate typed => typed.DataType is not null, + _ => true + }; + + if (!valid) + { + throw new InvalidOperationException("DataTemplate inside of DataTemplates must have a DataType set. Set DataType property or use ItemTemplate with single template instead."); + } } } } \ No newline at end of file diff --git a/src/Avalonia.Controls/Templates/ITypedDataTemplate.cs b/src/Avalonia.Controls/Templates/ITypedDataTemplate.cs new file mode 100644 index 0000000000..239dbd79f4 --- /dev/null +++ b/src/Avalonia.Controls/Templates/ITypedDataTemplate.cs @@ -0,0 +1,10 @@ +using System; +using Avalonia.Metadata; + +namespace Avalonia.Controls.Templates; + +public interface ITypedDataTemplate : IDataTemplate +{ + [DataType] + Type? DataType { get; } +} diff --git a/src/Markup/Avalonia.Markup.Xaml/Templates/DataTemplate.cs b/src/Markup/Avalonia.Markup.Xaml/Templates/DataTemplate.cs index d2b24979cc..4da6b1b791 100644 --- a/src/Markup/Avalonia.Markup.Xaml/Templates/DataTemplate.cs +++ b/src/Markup/Avalonia.Markup.Xaml/Templates/DataTemplate.cs @@ -5,7 +5,7 @@ using Avalonia.Metadata; namespace Avalonia.Markup.Xaml.Templates { - public class DataTemplate : IRecyclingDataTemplate + public class DataTemplate : IRecyclingDataTemplate, ITypedDataTemplate { [DataType] public Type DataType { get; set; } diff --git a/src/Markup/Avalonia.Markup.Xaml/Templates/TreeDataTemplate.cs b/src/Markup/Avalonia.Markup.Xaml/Templates/TreeDataTemplate.cs index 10061c3d48..04e8b0a9c0 100644 --- a/src/Markup/Avalonia.Markup.Xaml/Templates/TreeDataTemplate.cs +++ b/src/Markup/Avalonia.Markup.Xaml/Templates/TreeDataTemplate.cs @@ -9,7 +9,7 @@ using Avalonia.Metadata; namespace Avalonia.Markup.Xaml.Templates { - public class TreeDataTemplate : ITreeDataTemplate + public class TreeDataTemplate : ITreeDataTemplate, ITypedDataTemplate { [DataType] public Type DataType { get; set; } diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs index 7e721fd7b2..555a05638b 100644 --- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs +++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs @@ -413,11 +413,11 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests' x:DataType='local:TestDataContext'> - + - + "; var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml); diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlBindingTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlBindingTests.cs index 8188b212e1..affa292a7d 100644 --- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlBindingTests.cs +++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/ControlBindingTests.cs @@ -74,18 +74,18 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml - + - + - + - + "; diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs index 53881467e7..abbcf6c5a8 100644 --- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs +++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs @@ -1,3 +1,4 @@ +using System; using Avalonia.Controls; using Avalonia.Controls.Presenters; using Avalonia.UnitTests; @@ -132,5 +133,25 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml Assert.Same(viewModel.Child.Child, canvas.DataContext); } } + + [Fact] + public void DataTemplates_Without_Type_Should_Throw() + { + using (UnitTestApplication.Start(TestServices.StyledWindow)) + { + var xaml = @" + + + + + + + +"; + Assert.Throws(() => (Window)AvaloniaRuntimeXamlLoader.Load(xaml)); + } + } } } diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/TreeDataTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/TreeDataTemplateTests.cs index 3fdac49f31..807b37517a 100644 --- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/TreeDataTemplateTests.cs +++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/TreeDataTemplateTests.cs @@ -14,7 +14,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml { using (UnitTestApplication.Start(TestServices.MockPlatformWrapper)) { - var xaml = ""; + var xaml = ""; var templates = (DataTemplates)AvaloniaRuntimeXamlLoader.Load(xaml); var template = (TreeDataTemplate)(templates.First());