Improved constructor definition for [AlsoNotifyForAttribute] type

Author: Sergio0694

Microsoft.Toolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.cs

@@ -146,15 +146,36 @@ private static PropertyDeclarationSyntax CreatePropertyDeclaration(GeneratorExec
                 // Add dependent property notifications, if needed
                 if (SymbolEqualityComparer.Default.Equals(attributeData.AttributeClass, alsoNotifyForAttributeSymbol))
                 {
-                    foreach (TypedConstant attributeArgument in attributeData.ConstructorArguments[0].Values)
+                    foreach (TypedConstant attributeArgument in attributeData.ConstructorArguments)
                     {
-                        if (attributeArgument.Value is string dependentPropertyName)
+                        if (attributeArgument.IsNull)
+                        {
+                            continue;
+                        }
+
+                        if (attributeArgument.Kind == TypedConstantKind.Primitive &&
+                            attributeArgument.Value is string dependentPropertyName)
                         {
                             // OnPropertyChanged("OtherPropertyName");
                             dependentPropertyNotificationStatements.Add(ExpressionStatement(
                                 InvocationExpression(IdentifierName("OnPropertyChanged"))
                                 .AddArgumentListArguments(Argument(LiteralExpression(SyntaxKind.StringLiteralExpression, Literal(dependentPropertyName))))));
                         }
+                        else if (attributeArgument.Kind == TypedConstantKind.Array)
+                        {
+                            foreach (TypedConstant nestedAttributeArgument in attributeArgument.Values)
+                            {
+                                if (nestedAttributeArgument.IsNull)
+                                {
+                                    continue;
+                                }
+
+                                // Additional property names
+                                dependentPropertyNotificationStatements.Add(ExpressionStatement(
+                                    InvocationExpression(IdentifierName("OnPropertyChanged"))
+                                    .AddArgumentListArguments(Argument(LiteralExpression(SyntaxKind.StringLiteralExpression, Literal((string)nestedAttributeArgument.Value!))))));
+                            }
+                        }
                     }
                 }
                 else if (validationAttributeSymbol is not null &&

Microsoft.Toolkit.Mvvm/ComponentModel/Attributes/AlsoNotifyForAttribute.cs

@@ -6,6 +6,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Linq;
 
 namespace Microsoft.Toolkit.Mvvm.ComponentModel
 {
@@ -68,10 +69,23 @@ public sealed class AlsoNotifyForAttribute : Attribute
         /// <summary>
         /// Initializes a new instance of the <see cref="AlsoNotifyForAttribute"/> class.
         /// </summary>
-        /// <param name="propertyNames">The property names to also notify when the annotated property changes.</param>
-        public AlsoNotifyForAttribute(params string[] propertyNames)
+        /// <param name="propertyName">The name of the property to also notify when the annotated property changes.</param>
+        public AlsoNotifyForAttribute(string propertyName)
         {
-            PropertyNames = propertyNames;
+            PropertyNames = new[] { propertyName };
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AlsoNotifyForAttribute"/> class.
+        /// </summary>
+        /// <param name="propertyName">The name of the property to also notify when the annotated property changes.</param>
+        /// <param name="otherPropertyNames">
+        /// The other property names to also notify when the annotated property changes. This parameter can optionally
+        /// be used to indicate a series of dependent properties from the same attribute, to keep the code more compact.
+        /// </param>
+        public AlsoNotifyForAttribute(string propertyName, string[] otherPropertyNames)
+        {
+            PropertyNames = new[] { propertyName }.Concat(otherPropertyNames).ToArray();
         }
 
         /// <summary>