Add Support for DynamicData (#180)

* Add Support for DynamicData

* Update Docs

Author: ChrisPulman

README.md

@@ -24,6 +24,7 @@ ReactiveUI Source Generators automatically generate ReactiveUI objects to stream
 - `[IViewFor(nameof(ViewModelName))]`
 - `[RoutedControlHost("YourNameSpace.CustomControl")]`
 - `[ViewModelControlHost("YourNameSpace.CustomControl")]`
+- `[BindableDerivedList]` Generates a derived list from a ReadOnlyObservableCollection backing field
 
 ### Compatibility Notes
 - For ReactiveUI versions **older than V19.5.31**, all `[ReactiveCommand]` options are supported except for async methods with a `CancellationToken`.
@@ -521,6 +522,18 @@ public partial class MyReactiveControl : UserControl
 }
 ```
 
+### Usage ReadOnlyObservableCollection
+
+```csharp
+using ReactiveUI.SourceGenerators;
+
+public partial class MyReactiveClass
+{
+    [BindableDerivedList]
+    private readonly ReadOnlyObservableCollection<string> _myList;
+}
+```
+
 ## Platform specific Attributes
 
 ### WinForms

src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/BindableDerivedListGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs

@@ -0,0 +1,21 @@
+//HintName: ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.cs
+// Copyright (c) 2025 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System;
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// ReactiveAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[AttributeUsage(AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
+internal sealed class BindableDerivedListAttribute : Attribute;
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/ReactiveUI.SourceGenerators.Tests.csproj

@@ -35,6 +35,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <Folder Include="DERIVEDLIST\" />
     <Folder Include="IVIEWFOR\" />
     <Folder Include="OAPH\" />
     <Folder Include="REACTIVECMD\" />

src/ReactiveUI.SourceGenerator.Tests/TestHelper.cs

@@ -33,10 +33,10 @@ namespace ReactiveUI.SourceGenerator.Tests;
 public sealed class TestHelper<T>(ITestOutputHelper testOutput) : IDisposable
         where T : IIncrementalGenerator, new()
 {
+#pragma warning disable CS0618 // Type or member is obsolete
     /// <summary>
     /// Represents the NuGet library dependency for the Splat library.
     /// </summary>
-#pragma warning disable CS0618 // Type or member is obsolete
     private static readonly LibraryRange SplatLibrary =
         new("Splat", VersionRange.AllStableFloating, LibraryDependencyTarget.Package);
 
@@ -90,6 +90,7 @@ public string VerifiedFilePath()
             nameof(IViewForGenerator) => "IVIEWFOR",
             nameof(RoutedControlHostGenerator) => "ROUTEDHOST",
             nameof(ViewModelControlHostGenerator) => "CONTROLHOST",
+            nameof(BindableDerivedListGenerator) => "DERIVEDLIST",
             _ => name,
         };
     }

src/ReactiveUI.SourceGenerator.Tests/UnitTests/BindableDerivedListGeneratorTests.cs

@@ -0,0 +1,40 @@
+// Copyright (c) 2024 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using ReactiveUI.SourceGenerators;
+using Xunit.Abstractions;
+
+namespace ReactiveUI.SourceGenerator.Tests;
+
+/// <summary>
+/// BindableDerivedListGeneratorTests.
+/// </summary>
+public class BindableDerivedListGeneratorTests(ITestOutputHelper output) : TestBase<BindableDerivedListGenerator>(output)
+{
+    /// <summary>
+    /// Tests that the source generator correctly generates reactive properties.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Fact]
+    public Task FromReactiveProperties()
+    {
+        // Arrange: Setup the source code that matches the generator input expectations.
+        const string sourceCode = """
+                using System.Collections.ObjectModel;
+                using DynamicData;
+
+                namespace TestNs;
+
+                public partial class TestVM
+                {
+                    [BindableDerivedList]
+                    private ReadOnlyObservableCollection<int> _test1;
+                }
+            """;
+
+        // Act: Initialize the helper and run the generator. Assert: Verify the generated code.
+        return TestHelper.TestPass(sourceCode);
+    }
+}

src/ReactiveUI.SourceGenerators.Execute/Person.cs

@@ -0,0 +1,25 @@
+// Copyright (c) 2024 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using ReactiveUI;
+using ReactiveUI.SourceGenerators;
+
+namespace SGReactiveUI.SourceGenerators.Test;
+
+/// <summary>
+/// Person.
+/// </summary>
+/// <seealso cref="ReactiveUI.ReactiveObject" />
+public partial class Person : ReactiveObject
+{
+    /// <summary>
+    /// Gets or sets a value indicating whether this <see cref="Person"/> is deleted.
+    /// </summary>
+    /// <value>
+    ///   <c>true</c> if deleted; otherwise, <c>false</c>.
+    /// </value>
+    [Reactive]
+    public bool Deleted { get; set; }
+}

src/ReactiveUI.SourceGenerators.Execute/TestViewModel.cs

@@ -3,6 +3,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
+using System.Collections.ObjectModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Reactive;
 using System.Reactive.Concurrency;
@@ -11,6 +12,7 @@
 using System.Reactive.Subjects;
 using System.Runtime.Serialization;
 using System.Text.Json.Serialization;
+using DynamicData;
 using ReactiveUI;
 using ReactiveUI.SourceGenerators;
 
@@ -66,6 +68,12 @@ public partial class TestViewModel : ReactiveObject, IActivatableViewModel, IDis
     [Reactive(SetModifier = AccessModifier.Init, UseRequired = true)]
     private string _mustBeSet;
 
+    [Reactive]
+    private IEnumerable<Person> _people = [new Person()];
+
+    [BindableDerivedList]
+    private ReadOnlyObservableCollection<Person>? _visiblePeople;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="TestViewModel"/> class.
     /// </summary>
@@ -186,6 +194,15 @@ public TestViewModel()
         _observableAsPropertyFromPropertyHelper = _fromPartialTestSubject.ToProperty(this, x => x.ObservableAsPropertyFromProperty);
         _fromPartialTestSubject.OnNext(11);
         Console.Out.WriteLine($"Observable updated, value should be 11, value is : {ObservableAsPropertyFromProperty}");
+
+        this.WhenAnyValue(vm => vm.People)
+        .Subscribe(people => people
+            .AsObservableChangeSet()
+            .AutoRefresh(x => x.Deleted)
+            .Filter(x => !x.Deleted)
+            .Bind(out _visiblePeople)
+            .Subscribe());
+
         Console.ReadLine();
     }
 

src/ReactiveUI.SourceGenerators.Roslyn/AnalyzerReleases.Shipped.md

@@ -22,7 +22,7 @@ RXUISG0015 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https:/
 RXUISG0017 | ReactiveUI.SourceGenerators.ObservableAsPropertyFromObservableGenerator | Error | See https://www.reactiveui.net/docs/handbook/view-models/boilerplate-code.html
 RXUISG0018 | ReactiveUI.SourceGenerators.ObservableAsPropertyFromObservableGenerator | Error | See https://www.reactiveui.net/docs/handbook/view-models/boilerplate-code.html
 RXUISG0018 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/docs/handbook/view-models/boilerplate-code.html
-
+RXUISG0019 | ReactiveUI.SourceGenerators.BindableDerivedListGenerator | Error | See https://www.reactiveui.net/docs/handbook/view-models/boilerplate-code.html
 
 ## Rules
 Shipped in ReactiveUI.SourceGenerators
@@ -83,3 +83,6 @@ This rule checks if the `ObservableAsProperty` has Invalid class inheritance, mu
 
 - RXUISG0018 - ReactiveGenerator
 This rule checks if the `Reactive` has Invalid class inheritance, must inherit from `ReactiveObject`.
+
+- RXUISG0019 - BindableDerivedListGenerator
+- This rule checks if the `BindableDerivedList` has Invalid property inheritance type.

src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs

@@ -435,33 +435,29 @@ internal sealed class RoutedControlHostAttribute(string? baseType) : Attribute;
 #pragma warning restore
 """;
 
-    public const string IsExternalInitType = "System.Runtime.CompilerServices.IsExternalInit";
+    public const string BindableDerivedListAttributeType = "ReactiveUI.SourceGenerators.BindableDerivedListAttribute";
 
-    public static string IsExternalInit => $$"""
+    public static string BindableDerivedListAttribute => $$"""
 // Copyright (c) {{DateTime.Now.Year}} .NET Foundation and Contributors. All rights reserved.
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
-        
-// <auto-generated />
-#pragma warning disable
 
-#if !NET5_0_OR_GREATER
-
-namespace System.Runtime.CompilerServices;
+using System;
 
-using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
 
 /// <summary>
-/// Reserved to be used by the compiler for tracking metadata. This class should not be used by developers in source code.
+/// ReactiveAttribute.
 /// </summary>
-[ExcludeFromCodeCoverage]
-[DebuggerNonUserCode]
-static class IsExternalInit;
-
-#endif
-
+/// <seealso cref="Attribute" />
+[global::System.CodeDom.Compiler.GeneratedCode("{{ReactiveGenerator.GeneratorName}}", "{{ReactiveGenerator.GeneratorVersion}}")]
+[AttributeUsage(AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
+internal sealed class BindableDerivedListAttribute : Attribute;
+#nullable restore
 #pragma warning restore
 """;
 }