Add AlsoNotify support to ReactiveAttribute and generator

Introduces the AlsoNotify parameter to the ReactiveAttribute, allowing additional property change notifications to be specified. Updates the source generator to handle AlsoNotify, emitting RaisePropertyChanged calls for the specified properties in generated setters. Includes new and updated tests to verify the new behavior, and updates documentation to describe the new feature.

Author: ChrisPulman

README.md

@@ -28,6 +28,7 @@ ReactiveUI Source Generators automatically generate ReactiveUI objects to stream
 - `[Reactive(SetModifier = AccessModifier.Protected)]` With field and access modifiers, (Not Required for partial properties, configure set accessor with the property decalaration).
 - `[Reactive(Inheritance = InheritanceModifier.Virtual)]` With field and access modifiers. This will generate a virtual property.
 - `[Reactive(UseRequired = true)]` With field and access modifiers. This will generate a required property, (Not Required for partial properties, use required keyword for property decalaration).
+- `[Reactive(nameof(RaiseProperty1), nameof(RaiseProperty2))]` With field and property changed notification for additional properties.
 - `[ObservableAsProperty]` With field, method, Observable property and partial property support (C# 13 Visual Studio Version 17.12.0)
 - `[ObservableAsProperty(ReadOnly = false)]` Removes readonly keyword from the generated helper field
 - `[ObservableAsProperty(PropertyName = "ReadOnlyPropertyName")]`
@@ -91,6 +92,9 @@ Generates a derived list from a `ReadOnlyObservableCollection` backing field.
 ### `[ReactiveCollection]`
 Generates property changed notifications on add, remove, and new actions on an `ObservableCollection` backing field.
 
+### `[IReactiveObject]`
+Generates `IReactiveObject` implementation for classes not able to inherit from `ReactiveObject`.
+
 ## Historical Approach
 
 ### Read-Write Properties
@@ -685,7 +689,7 @@ public partial class MyReactiveClass : ReactiveObject
 }
 ```
 
-### ReactiveObject implementation for classes not able to inherit from ReactiveObject
+### IReactiveObject implementation for classes not able to inherit from ReactiveObject
 ```csharp
 using ReactiveUI;
 using ReactiveUI.SourceGenerators;

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveFromPartialWithAlsoNotify#ReactiveUI.SourceGenerators.AccessModifier.g.verified.cs

@@ -0,0 +1,58 @@
+//HintName: ReactiveUI.SourceGenerators.AccessModifier.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.
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// AccessModifier.
+/// </summary>
+internal enum AccessModifier
+{
+    Public,
+    Protected,
+    Internal,
+    Private,
+    InternalProtected,
+    PrivateProtected,
+    Init,
+}
+
+/// <summary>
+/// Property Access Modifier.
+/// </summary>
+internal enum PropertyAccessModifier
+{
+    Public,
+    Protected,
+    Internal,
+    Private,
+    InternalProtected,
+    PrivateProtected,
+}
+
+/// <summary>
+/// InheritanceModifier.
+/// </summary>
+internal enum InheritanceModifier
+{
+    None,
+    Virtual,
+    Override,
+    New,
+}
+
+internal enum SplatRegistrationType
+{
+    None,
+    LazySingleton,
+    Constant,
+    PerRequest,
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveFromPartialWithAlsoNotify#ReactiveUI.SourceGenerators.ReactiveAttribute.g.verified.cs

@@ -0,0 +1,51 @@
+//HintName: ReactiveUI.SourceGenerators.ReactiveAttribute.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.
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// ReactiveAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[global::System.AttributeUsage(global::System.AttributeTargets.Field | global::System.AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
+internal sealed class ReactiveAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReactiveAttribute"/> class.
+    /// </summary>
+    public ReactiveAttribute(params string[] alsoNotify)
+    {
+        AlsoNotify = alsoNotify;
+    }
+
+    /// <summary>
+    /// Gets the AccessModifier of the set property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the set property.
+    /// </value>
+    public AccessModifier SetModifier { get; init; }
+
+    /// <summary>
+    /// Gets the InheritanceModifier of the property.
+    /// </sumary>
+    public InheritanceModifier Inheritance { get; init; }
+
+    /// <summary>
+    /// Use Required attribute to indicate that the property is required.
+    /// </summary>
+    public bool UseRequired { get; init; }
+
+    /// <summary>
+    /// Gets the AlsoNotify properties to raise change notifications for.
+    /// </summary>
+    public string[]? AlsoNotify { get; }
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveFromPartialWithAlsoNotify#TestNs.TestVM.Properties.g.verified.cs

@@ -0,0 +1,28 @@
+//HintName: TestNs.TestVM.Properties.g.cs
+// <auto-generated/>
+using ReactiveUI;
+
+#pragma warning disable
+#nullable enable
+
+namespace TestNs
+{
+    
+    public partial class TestVM
+    {
+        
+        /// <inheritdoc cref="_test4"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        public int Test4
+        { 
+            get => _test4;
+            [global::System.Diagnostics.CodeAnalysis.MemberNotNull("_test4")]
+            set
+            {
+                this.RaiseAndSetIfChanged(ref _test4, value);                
+            }
+        }
+    }
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactivePartialProperties#ReactiveUI.SourceGenerators.ReactiveAttribute.g.verified.cs

@@ -16,6 +16,14 @@ namespace ReactiveUI.SourceGenerators;
 [global::System.AttributeUsage(global::System.AttributeTargets.Field | global::System.AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
 internal sealed class ReactiveAttribute : global::System.Attribute
 {
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReactiveAttribute"/> class.
+    /// </summary>
+    public ReactiveAttribute(params string[] alsoNotify)
+    {
+        AlsoNotify = alsoNotify;
+    }
+
     /// <summary>
     /// Gets the AccessModifier of the set property.
     /// </summary>
@@ -33,6 +41,11 @@ internal sealed class ReactiveAttribute : global::System.Attribute
     /// Use Required attribute to indicate that the property is required.
     /// </summary>
     public bool UseRequired { get; init; }
+
+    /// <summary>
+    /// Gets the AlsoNotify properties to raise change notifications for.
+    /// </summary>
+    public string[]? AlsoNotify { get; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveProperiesWithAttributes#ReactiveUI.SourceGenerators.ReactiveAttribute.g.verified.cs

@@ -16,6 +16,14 @@ namespace ReactiveUI.SourceGenerators;
 [global::System.AttributeUsage(global::System.AttributeTargets.Field | global::System.AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
 internal sealed class ReactiveAttribute : global::System.Attribute
 {
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReactiveAttribute"/> class.
+    /// </summary>
+    public ReactiveAttribute(params string[] alsoNotify)
+    {
+        AlsoNotify = alsoNotify;
+    }
+
     /// <summary>
     /// Gets the AccessModifier of the set property.
     /// </summary>
@@ -33,6 +41,11 @@ internal sealed class ReactiveAttribute : global::System.Attribute
     /// Use Required attribute to indicate that the property is required.
     /// </summary>
     public bool UseRequired { get; init; }
+
+    /// <summary>
+    /// Gets the AlsoNotify properties to raise change notifications for.
+    /// </summary>
+    public string[]? AlsoNotify { get; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveProperiesWithAttributes#TestNs.TestVM.Properties.g.verified.cs

@@ -19,7 +19,10 @@ public int Test3
         { 
             get => _test3;
             [global::System.Diagnostics.CodeAnalysis.MemberNotNull("_test3")]
-            set => this.RaiseAndSetIfChanged(ref _test3, value);
+            set
+            {
+                this.RaiseAndSetIfChanged(ref _test3, value);                
+            }
         }
     }
 }

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.ReactiveAttribute.g.verified.cs

@@ -16,6 +16,14 @@ namespace ReactiveUI.SourceGenerators;
 [global::System.AttributeUsage(global::System.AttributeTargets.Field | global::System.AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
 internal sealed class ReactiveAttribute : global::System.Attribute
 {
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReactiveAttribute"/> class.
+    /// </summary>
+    public ReactiveAttribute(params string[] alsoNotify)
+    {
+        AlsoNotify = alsoNotify;
+    }
+
     /// <summary>
     /// Gets the AccessModifier of the set property.
     /// </summary>
@@ -33,6 +41,11 @@ internal sealed class ReactiveAttribute : global::System.Attribute
     /// Use Required attribute to indicate that the property is required.
     /// </summary>
     public bool UseRequired { get; init; }
+
+    /// <summary>
+    /// Gets the AlsoNotify properties to raise change notifications for.
+    /// </summary>
+    public string[]? AlsoNotify { get; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactiveProperties#TestNs.TestVM.Properties.g.verified.cs

@@ -17,7 +17,10 @@ public int Test1
         { 
             get => _test1;
             [global::System.Diagnostics.CodeAnalysis.MemberNotNull("_test1")]
-            set => this.RaiseAndSetIfChanged(ref _test1, value);
+            set
+            {
+                this.RaiseAndSetIfChanged(ref _test1, value);                
+            }
         }
     }
 }

src/ReactiveUI.SourceGenerator.Tests/REACTIVE/ReactiveGeneratorTests.FromReactivePropertiesCalledValue#ReactiveUI.SourceGenerators.ReactiveAttribute.g.verified.cs

@@ -16,6 +16,14 @@ namespace ReactiveUI.SourceGenerators;
 [global::System.AttributeUsage(global::System.AttributeTargets.Field | global::System.AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
 internal sealed class ReactiveAttribute : global::System.Attribute
 {
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReactiveAttribute"/> class.
+    /// </summary>
+    public ReactiveAttribute(params string[] alsoNotify)
+    {
+        AlsoNotify = alsoNotify;
+    }
+
     /// <summary>
     /// Gets the AccessModifier of the set property.
     /// </summary>
@@ -33,6 +41,11 @@ internal sealed class ReactiveAttribute : global::System.Attribute
     /// Use Required attribute to indicate that the property is required.
     /// </summary>
     public bool UseRequired { get; init; }
+
+    /// <summary>
+    /// Gets the AlsoNotify properties to raise change notifications for.
+    /// </summary>
+    public string[]? AlsoNotify { get; }
 }
 #nullable restore
 #pragma warning restore