Add AsyncLazyCommand.

Author: ChebanovDD

samples/Unity.Mvvm.ToDoList/Assets/Scripts/ViewModels/MainViewModel.cs

@@ -23,8 +23,8 @@ public MainViewModel(IAppContext appContext)
             TaskItems = new ObservableCollection<TaskItemData>();
             TaskItems.CollectionChanged += OnTaskItemsCollectionChanged;
 
-            ShowAddTaskDialogCommand = new AsyncCommand(SetAddTaskDialogActive);
-            HideAddTaskDialogCommand = new AsyncCommand(HideAddTaskDialogAsync, IsAddTaskDialogActive);
+            ShowAddTaskDialogCommand = new AsyncLazyCommand(SetAddTaskDialogActive);
+            HideAddTaskDialogCommand = new AsyncLazyCommand(HideAddTaskDialogAsync, IsAddTaskDialogActive);
 
             SubscribeOnTaskAddMessage(appContext.Resolve<TaskBroker>()).Forget();
         }

src/UnityMvvmToolkit.UnityPackage/Assets/Plugins/UnityMvvmToolkit/Runtime/External/UniTask/AsyncCommand.cs

@@ -9,27 +9,23 @@ namespace UnityMvvmToolkit.UniTask
 
     public class AsyncCommand : BaseAsyncCommand, IAsyncCommand
     {
-        private readonly Func<CancellationToken, UniTask> _action;
-
         public AsyncCommand(Func<CancellationToken, UniTask> action, Func<bool> canExecute = null) : base(canExecute)
         {
-            _action = action;
+            Action = action;
         }
 
+        protected Func<CancellationToken, UniTask> Action { get; }
+
         public void Execute()
         {
             ExecuteAsync().Forget();
         }
 
-        public async UniTask ExecuteAsync(CancellationToken cancellationToken = default)
+        public virtual async UniTask ExecuteAsync(CancellationToken cancellationToken = default)
         {
-            if (ExecuteTask?.Task.Status.IsCompleted() ?? true)
-            {
-                ExecuteTask = _action.Invoke(cancellationToken).ToAsyncLazy();
-            }
-
             try
             {
+                ExecuteTask = Action.Invoke(cancellationToken).ToAsyncLazy();
                 await ExecuteTask;
             }
             finally
@@ -41,27 +37,23 @@ public async UniTask ExecuteAsync(CancellationToken cancellationToken = default)
 
     public class AsyncCommand<T> : BaseAsyncCommand, IAsyncCommand<T>
     {
-        private readonly Func<T, CancellationToken, UniTask> _action;
-
         public AsyncCommand(Func<T, CancellationToken, UniTask> action, Func<bool> canExecute = null) : base(canExecute)
         {
-            _action = action;
+            Action = action;
         }
 
+        protected Func<T, CancellationToken, UniTask> Action { get; }
+
         public void Execute(T parameter)
         {
             ExecuteAsync(parameter).Forget();
         }
 
-        public async UniTask ExecuteAsync(T parameter, CancellationToken cancellationToken = default)
+        public virtual async UniTask ExecuteAsync(T parameter, CancellationToken cancellationToken = default)
         {
-            if (ExecuteTask?.Task.Status.IsCompleted() ?? true)
-            {
-                ExecuteTask = _action.Invoke(parameter, cancellationToken).ToAsyncLazy();
-            }
-
             try
             {
+                ExecuteTask = Action.Invoke(parameter, cancellationToken).ToAsyncLazy();
                 await ExecuteTask;
             }
             finally

src/UnityMvvmToolkit.UnityPackage/Assets/Plugins/UnityMvvmToolkit/Runtime/External/UniTask/AsyncCommand.cs.meta

@@ -0,0 +1,60 @@
+#if UNITYMVVMTOOLKIT_UNITASK_SUPPORT
+
+namespace UnityMvvmToolkit.UniTask
+{
+    using System;
+    using System.Threading;
+    using Cysharp.Threading.Tasks;
+
+    public class AsyncLazyCommand : AsyncCommand
+    {
+        public AsyncLazyCommand(Func<CancellationToken, UniTask> action, Func<bool> canExecute = null)
+            : base(action, canExecute)
+        {
+        }
+
+        public override async UniTask ExecuteAsync(CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                if (ExecuteTask?.Task.Status.IsCompleted() ?? true)
+                {
+                    ExecuteTask = Action.Invoke(cancellationToken).ToAsyncLazy();
+                }
+
+                await ExecuteTask;
+            }
+            finally
+            {
+                ExecuteTask = null;
+            }
+        }
+    }
+
+    public class AsyncLazyCommand<T> : AsyncCommand<T>
+    {
+        public AsyncLazyCommand(Func<T, CancellationToken, UniTask> action, Func<bool> canExecute = null)
+            : base(action, canExecute)
+        {
+        }
+
+        public override async UniTask ExecuteAsync(T parameter, CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                if (ExecuteTask?.Task.Status.IsCompleted() ?? true)
+                {
+                    ExecuteTask = Action.Invoke(parameter, cancellationToken).ToAsyncLazy();
+                }
+
+                await ExecuteTask;
+            }
+            finally
+            {
+                ExecuteTask = null;
+            }
+        }
+    }
+}
+
+#endif