Fix: command binding now against commandsource on control instead of command property (#417)

* move icommand properties back to simple binding

* Generated Command Binding based on class interface

* bind to icommand

* first part of apply binding

* simplify command binding generics

Author: dpvreony

src/ReactiveUI.WPF.SampleApp/ViewBindingModels/QuestionnaireViewBindingModels.cs

@@ -6,6 +6,7 @@
 using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Windows.Controls;
+using System.Windows.Input;
 using System.Windows.Media;
 using ReactiveUI.WPF.SampleApp.ViewModels;
 using ReactiveUI.WPF.SampleApp.Views;
@@ -25,7 +26,7 @@ protected override IEnumerable<IControlBindingModel<QuestionnaireView, Questionn
             // launch interaction
             yield return new ButtonControlBindingModel<QuestionnaireView, QuestionnaireViewModel>(vw => vw.LaunchInteraction)
             {
-                Command = new CommandBinding<QuestionnaireViewModel>(vm => vm.LaunchInteraction)
+                BindCommand = new CommandBinding<QuestionnaireViewModel>(vm => vm.LaunchInteraction)
             };
 
             // Forename

src/Vetuviem.Blazor.SourceGenerator/BlazorPlatformResolver.cs

@@ -29,6 +29,12 @@ public string GetBaseUiElement()
             return "global::Microsoft.AspNetCore.Components.IComponent";
         }
 
+        /// <inheritdoc />
+        public string? GetCommandSourceInterface()
+        {
+            return null;
+        }
+
         /// <inheritdoc />
         public string? GetCommandInterface()
         {

src/Vetuviem.Core/CommandBinding.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Linq.Expressions;
-using System.Reactive;
 using System.Reactive.Disposables;
 using System.Windows.Input;
 using ReactiveUI;
@@ -15,10 +14,10 @@ namespace Vetuviem.Core
     /// Represents a command binding between a control and a viewmodel.
     /// </summary>
     /// <typeparam name="TViewModel">The type for the viewmodel.</typeparam>
-    public sealed class CommandBinding<TViewModel> : ICommandBinding<TViewModel, ICommand>
+    public sealed class CommandBinding<TViewModel> : ICommandBinding<TViewModel>
         where TViewModel : class
     {
-        private readonly Expression<Func<TViewModel, ReactiveCommand<Unit, Unit>?>> _viewModelBinding;
+        private readonly Expression<Func<TViewModel, ICommand?>> _viewModelBinding;
         private readonly string? _toEvent;
 
         /// <summary>
@@ -27,19 +26,19 @@ public sealed class CommandBinding<TViewModel> : ICommandBinding<TViewModel, ICo
         /// <param name="viewModelBinding">Expression for the View Model binding.</param>
         /// <param name="toEvent">If specified, bind to the specific event instead of the default.</param>
         public CommandBinding(
-            Expression<Func<TViewModel, ReactiveCommand<Unit, Unit>?>> viewModelBinding,
+            Expression<Func<TViewModel, ICommand?>> viewModelBinding,
             string? toEvent = null)
         {
             _viewModelBinding = viewModelBinding;
             _toEvent = toEvent;
         }
 
         /// <inheritdoc/>
-        public void ApplyBinding<TView>(
+        public void ApplyBinding<TView, TViewProp>(
             Action<IDisposable> disposeAction,
             TView view,
             TViewModel viewModel,
-            Expression<Func<TView, ICommand>> viewBinding)
+            Expression<Func<TView, TViewProp>> viewBinding)
             where TView : class, IViewFor<TViewModel>
         {
             if (disposeAction == null)
@@ -70,11 +69,11 @@ public void ApplyBinding<TView>(
         }
 
         /// <inheritdoc/>
-        public void ApplyBinding<TView>(
+        public void ApplyBinding<TView, TViewProp>(
             CompositeDisposable compositeDisposable,
             TView view,
             TViewModel viewModel,
-            Expression<Func<TView, ICommand>> viewBinding)
+            Expression<Func<TView, TViewProp>> viewBinding)
             where TView : class, IViewFor<TViewModel>
         {
             if (compositeDisposable == null)

src/Vetuviem.Core/ICommandBinding.cs

@@ -13,19 +13,19 @@ namespace Vetuviem.Core
     /// Represents a View to View Model Binding for Commands.
     /// </summary>
     /// <typeparam name="TViewModel">The type for the ViewModel.</typeparam>
-    /// <typeparam name="TViewProp">The type for the View.</typeparam>
-    public interface ICommandBinding<TViewModel, TViewProp>
+    public interface ICommandBinding<TViewModel>
         where TViewModel : class
     {
         /// <summary>
         /// Applies a View to View Model Binding.
         /// </summary>
         /// <typeparam name="TView">The type for the view.</typeparam>
+        /// <typeparam name="TViewProp">The type for the View Property.</typeparam>
         /// <param name="d">The disposable action registration. Used to clean up when bindings fall out of scope.</param>
         /// <param name="view">The instance of the View to bind.</param>
         /// <param name="viewModel">The instance of the ViewModel to Bind.</param>
         /// <param name="viewBinding">Expression of the View Property to Bind to.</param>
-        void ApplyBinding<TView>(
+        void ApplyBinding<TView, TViewProp>(
             Action<IDisposable> d,
             TView view,
             TViewModel viewModel,
@@ -36,11 +36,12 @@ void ApplyBinding<TView>(
         /// Applies a View to View Model Binding.
         /// </summary>
         /// <typeparam name="TView">The type for the view.</typeparam>
+        /// <typeparam name="TViewProp">The type for the View Property.</typeparam>
         /// <param name="compositeDisposable">The disposable action registration. Used to clean up when bindings fall out of scope.</param>
         /// <param name="view">The instance of the View to bind.</param>
         /// <param name="viewModel">The instance of the ViewModel to Bind.</param>
         /// <param name="viewBinding">Expression of the View Property to Bind to.</param>
-        void ApplyBinding<TView>(
+        void ApplyBinding<TView, TViewProp>(
             CompositeDisposable compositeDisposable,
             TView view,
             TViewModel viewModel,

src/Vetuviem.SourceGenerator/AbstractBaseSourceGenerator.cs

@@ -230,7 +230,7 @@ public void Execute(GeneratorExecutionContext context)
                     return namespaceDeclaration;
             }
 
-            var desiredCommandInterface = platformResolver.GetCommandInterface();
+            var desiredCommandInterface = platformResolver.GetCommandSourceInterface();
 
             var generatorProcessor = new TGeneratorProcessor();
 
@@ -247,7 +247,8 @@ public void Execute(GeneratorExecutionContext context)
                 platformName,
                 namespaceName,
                 makeClassesPublic,
-                includeObsoleteItems);
+                includeObsoleteItems,
+                platformResolver.GetCommandInterface());
 
             return result;
         }

src/Vetuviem.SourceGenerator/Features/ControlBindingModels/AbstractControlBindingModelClassGenerator.cs

@@ -25,7 +25,8 @@ public ClassDeclarationSyntax GenerateClass(
             string platformName,
             string rootNamespace,
             bool makeClassesPublic,
-            bool includeObsoleteItems)
+            bool includeObsoleteItems,
+            string? platformCommandType)
         {
             var typeParameterList = GetTypeParameterListSyntax(namedTypeSymbol);
 
@@ -60,7 +61,8 @@ public ClassDeclarationSyntax GenerateClass(
                 controlClassFullName,
                 platformName,
                 makeClassesPublic,
-                includeObsoleteItems);
+                includeObsoleteItems,
+                platformCommandType);
 
             return classDeclaration
                 .WithModifiers(modifiers)
@@ -191,7 +193,8 @@ protected abstract SyntaxList<MemberDeclarationSyntax> ApplyMembers(
             string controlClassFullName,
             string platformName,
             bool makeClassesPublic,
-            bool includeObsoleteItems);
+            bool includeObsoleteItems,
+            string? platformCommandType);
 
         /// <summary>
         /// Gets the class name identifier from a named type symbol.

src/Vetuviem.SourceGenerator/Features/ControlBindingModels/ControlBindingModelPropertyGenerator.cs

@@ -30,7 +30,8 @@ public static SyntaxList<MemberDeclarationSyntax> GetProperties(
             INamedTypeSymbol namedTypeSymbol,
             string? desiredCommandInterface,
             bool makeClassesPublic,
-            bool includeObsoleteItems)
+            bool includeObsoleteItems,
+            string? platformCommandType)
         {
             if (namedTypeSymbol == null)
             {
@@ -42,8 +43,21 @@ public static SyntaxList<MemberDeclarationSyntax> GetProperties(
                 .Where(x => x.Kind == SymbolKind.Property)
                 .ToArray();
 
+            var fullName = namedTypeSymbol.GetFullName();
+
             var nodes = new List<MemberDeclarationSyntax>(properties.Length);
 
+            if (!string.IsNullOrWhiteSpace(desiredCommandInterface)
+                && !string.IsNullOrWhiteSpace(platformCommandType)
+                && namedTypeSymbol.Interfaces.Any(interfaceName => interfaceName.GetFullName().Equals(desiredCommandInterface, StringComparison.Ordinal)))
+            {
+                var bindCommandPropertyDeclaration = GetBindCommandPropertyDeclaration(
+                    makeClassesPublic,
+                    fullName,
+                    platformCommandType!);
+                nodes.Add(bindCommandPropertyDeclaration);
+            }
+
             foreach (var prop in properties)
             {
                 var propertySymbol = prop as IPropertySymbol;
@@ -74,15 +88,7 @@ public static SyntaxList<MemberDeclarationSyntax> GetProperties(
                     continue;
                 }
 
-                var accessorList = new[]
-                {
-                    SyntaxFactory.AccessorDeclaration(SyntaxKind.GetAccessorDeclaration)
-                        .WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken)),
-                    SyntaxFactory.AccessorDeclaration(SyntaxKind.InitAccessorDeclaration)
-                        .WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken))
-                };
-
-                var fullName = namedTypeSymbol.GetFullName();
+                var accessorList = GetAccessorDeclarationSyntaxes();
 
                 var summary = XmlSyntaxFactory.GenerateSummarySeeAlsoComment(
                     "Gets or sets the binding logic for {0}",
@@ -101,6 +107,36 @@ public static SyntaxList<MemberDeclarationSyntax> GetProperties(
             return new SyntaxList<MemberDeclarationSyntax>(nodes);
         }
 
+        private static AccessorDeclarationSyntax[] GetAccessorDeclarationSyntaxes()
+        {
+            var accessorList = new[]
+            {
+                SyntaxFactory.AccessorDeclaration(SyntaxKind.GetAccessorDeclaration)
+                    .WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken)),
+                SyntaxFactory.AccessorDeclaration(SyntaxKind.InitAccessorDeclaration)
+                    .WithSemicolonToken(SyntaxFactory.Token(SyntaxKind.SemicolonToken))
+            };
+            return accessorList;
+        }
+
+        private static MemberDeclarationSyntax GetBindCommandPropertyDeclaration(
+            bool makeClassesPublic,
+            string fullName,
+            string platformCommandType)
+        {
+            var accessorList = GetAccessorDeclarationSyntaxes();
+
+            var summary = XmlSyntaxFactory.GenerateSummarySeeAlsoComment(
+                "Gets or sets the command binding logic for {0}",
+                fullName);
+
+            return GetBindCommandPropertyDeclaration(
+                accessorList,
+                summary,
+                makeClassesPublic,
+                platformCommandType);
+        }
+
         private static bool ReplacesBaseProperty(
             IPropertySymbol propertySymbol,
             INamedTypeSymbol namedTypeSymbol)
@@ -128,6 +164,25 @@ private static bool ReplacesBaseProperty(
             return false;
         }
 
+        private static PropertyDeclarationSyntax GetBindCommandPropertyDeclaration(
+            AccessorDeclarationSyntax[] accessorList,
+            IEnumerable<SyntaxTrivia> summary,
+            bool makeClassesPublic,
+            string platformCommandType)
+        {
+            TypeSyntax type = GetCommandBindingTypeSyntax(platformCommandType);
+
+            var result = SyntaxFactory.PropertyDeclaration(
+                    type,
+                    "BindCommand")
+                .AddModifiers(SyntaxFactory.Token(makeClassesPublic ? SyntaxKind.PublicKeyword : SyntaxKind.InternalKeyword))
+                .WithAccessorList(
+                    SyntaxFactory.AccessorList(SyntaxFactory.List(accessorList)))
+                .WithLeadingTrivia(summary);
+
+            return result;
+        }
+
         private static PropertyDeclarationSyntax GetPropertyDeclaration(
             IPropertySymbol prop,
             AccessorDeclarationSyntax[] accessorList,
@@ -148,6 +203,12 @@ private static PropertyDeclarationSyntax GetPropertyDeclaration(
             return result;
         }
 
+        private static TypeSyntax GetCommandBindingTypeSyntax(string platformCommandType)
+        {
+            var type = SyntaxFactory.ParseTypeName($"global::Vetuviem.Core.ICommandBinding<TViewModel>?");
+            return type;
+        }
+
         private static TypeSyntax GetBindingTypeSyntax(
             IPropertySymbol prop,
             string? desiredCommandInterface)
@@ -165,17 +226,6 @@ private static string GetBindingInterfaceName(
             IPropertySymbol prop,
             string? desiredCommandInterface)
         {
-            if (!string.IsNullOrWhiteSpace(desiredCommandInterface))
-            {
-                var propType = prop.Type;
-                var isCommand = propType.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat).Equals(desiredCommandInterface, StringComparison.Ordinal)
-                    || propType.AllInterfaces.Any(interfaceName => interfaceName.GetFullName().Equals(desiredCommandInterface, StringComparison.Ordinal));
-                if (isCommand)
-                {
-                    return "ICommandBinding";
-                }
-            }
-
             var bindingType = prop.IsReadOnly ? "One" : "OneOrTwo";
 
             return $"I{bindingType}WayBind";

src/Vetuviem.SourceGenerator/Features/ControlBindingModels/ControlBoundControlBindingModelClassGenerator.cs

@@ -32,7 +32,8 @@ protected override SyntaxList<MemberDeclarationSyntax> ApplyMembers(
             string controlClassFullName,
             string platformName,
             bool makeClassesPublic,
-            bool includeObsoleteItems)
+            bool includeObsoleteItems,
+            string? platformCommandType)
         {
             return members;
         }