From 67f9547daf721177c67d5f81e9326f4c2718e1bb Mon Sep 17 00:00:00 2001
From: Ali Yousefi <ali.visual.studio@gmail.com>
Date: Mon, 13 Nov 2023 09:08:42 +0330
Subject: [PATCH] Add Support for TaskRelayCommand and IBusyViewModel

---
 .../BaseViewModel.cs                          |  11 +-
 .../Commands/BaseCommand.cs                   |  63 ++++++++++-
 .../Commands/TaskBaseCommand.cs               | 106 ++++++++++++++++++
 .../Commands/TaskRelayCommand.cs              | 106 ++++++++++++++++++
 .../EasyMicroservices.UI.Core.Mvvm.csproj     |   2 +-
 .../Interfaces/IBusyViewModel.cs              |  38 +++++++
 6 files changed, 317 insertions(+), 9 deletions(-)
 create mode 100644 src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskBaseCommand.cs
 create mode 100644 src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskRelayCommand.cs
 create mode 100644 src/CSharp/EasyMicroservices.UI.Core.Mvvm/Interfaces/IBusyViewModel.cs

diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/BaseViewModel.cs b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/BaseViewModel.cs
index 76fe373..412d7b2 100644
--- a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/BaseViewModel.cs
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/BaseViewModel.cs
@@ -1,4 +1,5 @@
 using EasyMicroservices.ServiceContracts;
+using EasyMicroservices.UI.Core.Interfaces;
 using System;
 using System.ComponentModel;
 using System.Threading.Tasks;
@@ -8,8 +9,13 @@ namespace EasyMicroservices.UI.Core;
 /// <summary>
 /// 
 /// </summary>
-public abstract class BaseViewModel : INotifyPropertyChanged
+public abstract class BaseViewModel : IBusyViewModel, INotifyPropertyChanged
 {
+    /// <summary>
+    /// 
+    /// </summary>
+    public Action<bool> OnBusyChanged { get; set; }
+
     bool _IsBusy;
     /// <summary>
     /// 
@@ -20,6 +26,7 @@ public virtual bool IsBusy
         set
         {
             _IsBusy = value;
+            OnBusyChanged?.Invoke(value);
             OnPropertyChanged(nameof(IsBusy));
         }
     }
@@ -128,7 +135,7 @@ public virtual async Task ExecuteApi(Func<Task<object>> getServerResult, Func<Ta
     /// </summary>
     /// <param name="exception"></param>
     /// <returns></returns>
-    public virtual Task DisplayError(Exception exception)
+    public virtual Task OnError(Exception exception)
     {
         return Task.CompletedTask;
     }
diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/BaseCommand.cs b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/BaseCommand.cs
index cd8c9e7..a27c467 100644
--- a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/BaseCommand.cs
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/BaseCommand.cs
@@ -1,4 +1,5 @@
-using System;
+using EasyMicroservices.UI.Core.Interfaces;
+using System;
 using System.Windows.Input;
 
 namespace EasyMicroservices.UI.Core.Commands;
@@ -12,8 +13,18 @@ public abstract class BaseCommand : ICommand
     /// 
     /// </summary>
     public event EventHandler CanExecuteChanged;
-    private readonly Action<object> _execute = null;
-    private readonly Func<object, bool> _canExecute = null;
+    /// <summary>
+    /// 
+    /// </summary>
+    protected readonly Action<object> _execute = null;
+    /// <summary>
+    /// 
+    /// </summary>
+    protected readonly Func<object, bool> _canExecute = null;
+    /// <summary>
+    /// /
+    /// </summary>
+    protected readonly IBusyViewModel _busyViewModel = null;
 
     /// <summary>
     /// 
@@ -26,6 +37,19 @@ public BaseCommand(Action<object> execute, Func<object, bool> canExecute)
         _canExecute = canExecute;
     }
 
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="busyViewModel"></param>
+    /// <param name="execute"></param>
+    /// <param name="canExecute"></param>
+    public BaseCommand(IBusyViewModel busyViewModel, Action<object> execute, Func<object, bool> canExecute)
+    {
+        _execute = execute;
+        _canExecute = canExecute;
+        _busyViewModel = busyViewModel;
+    }
+
     /// <summary>
     /// 
     /// </summary>
@@ -33,8 +57,15 @@ public BaseCommand(Action<object> execute, Func<object, bool> canExecute)
     /// <returns></returns>
     public virtual bool CanExecute(object parameter = null)
     {
-        CanExecuteChanged?.Invoke(this, new EventArgs());
-        return _canExecute == null || _canExecute(parameter);
+        try
+        {
+            return _canExecute == null || _canExecute(parameter);
+        }
+        catch (Exception ex)
+        {
+            _busyViewModel?.OnError(ex);
+            throw;
+        }
     }
 
     /// <summary>
@@ -43,6 +74,26 @@ public virtual bool CanExecute(object parameter = null)
     /// <param name="parameter"></param>
     public virtual void Execute(object parameter)
     {
-        _execute(parameter);
+        try
+        {
+            if (_busyViewModel != null)
+            {
+                _busyViewModel.Busy();
+                CanExecuteChanged?.Invoke(this, new EventArgs());
+            }
+            _execute(parameter);
+        }
+        catch (Exception ex)
+        {
+            _busyViewModel?.OnError(ex);
+        }
+        finally
+        {
+            if (_busyViewModel != null)
+            {
+                _busyViewModel.UnBusy();
+                CanExecuteChanged?.Invoke(this, new EventArgs());
+            }
+        }
     }
 }
diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskBaseCommand.cs b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskBaseCommand.cs
new file mode 100644
index 0000000..9da5e67
--- /dev/null
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskBaseCommand.cs
@@ -0,0 +1,106 @@
+using EasyMicroservices.UI.Core.Interfaces;
+using System;
+using System.Threading.Tasks;
+using System.Windows.Input;
+
+namespace EasyMicroservices.UI.Core.Commands
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public class TaskBaseCommand : ICommand
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        public event EventHandler CanExecuteChanged;
+        /// <summary>
+        /// 
+        /// </summary>
+        protected readonly Func<object, Task> _execute = null;
+        /// <summary>
+        /// 
+        /// </summary>
+        protected readonly Func<object, bool> _canExecute = null;
+        /// <summary>
+        /// /
+        /// </summary>
+        protected readonly IBusyViewModel _busyViewModel = null;
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskBaseCommand(Func<object, Task> execute, Func<object, bool> canExecute)
+        {
+            _execute = execute;
+            _canExecute = canExecute;
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="busyViewModel"></param>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskBaseCommand(IBusyViewModel busyViewModel, Func<object, Task> execute, Func<object, bool> canExecute)
+        {
+            _execute = execute;
+            _canExecute = canExecute;
+            _busyViewModel = busyViewModel;
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="parameter"></param>
+        /// <returns></returns>
+        public virtual bool CanExecute(object parameter = null)
+        {
+            try
+            {
+                return _canExecute == null || _canExecute(parameter);
+            }
+            catch (Exception ex)
+            {
+                _busyViewModel?.OnError(ex);
+                throw;
+            }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="parameter"></param>
+        public virtual void Execute(object parameter)
+        {
+            if (_busyViewModel != null)
+            {
+                _busyViewModel.Busy();
+                CanExecuteChanged?.Invoke(this, new EventArgs());
+            }
+            _ = InternalExecute(parameter);
+        }
+
+        async Task InternalExecute(object parameter)
+        {
+            try
+            {
+                await _execute(parameter);
+            }
+            catch (Exception ex)
+            {
+                _busyViewModel?.OnError(ex);
+            }
+            finally
+            {
+                if (_busyViewModel != null)
+                {
+                    _busyViewModel.UnBusy();
+                    CanExecuteChanged?.Invoke(this, new EventArgs());
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskRelayCommand.cs b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskRelayCommand.cs
new file mode 100644
index 0000000..4f86cbb
--- /dev/null
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Commands/TaskRelayCommand.cs
@@ -0,0 +1,106 @@
+using EasyMicroservices.UI.Core.Interfaces;
+using System;
+using System.Threading.Tasks;
+
+namespace EasyMicroservices.UI.Core.Commands
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public class TaskRelayCommand : TaskBaseCommand
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskRelayCommand(Func<Task> execute, Func<bool> canExecute)
+            : this(default, execute, canExecute)
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="execute"></param>
+        public TaskRelayCommand(Func<Task> execute)
+            : this(default, execute, () => true)
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="busyViewModel"></param>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskRelayCommand(IBusyViewModel busyViewModel, Func<Task> execute, Func<bool> canExecute)
+            : base(busyViewModel, (x) => execute(), (x) => canExecute())
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="busyViewModel"></param>
+        /// <param name="execute"></param>
+        public TaskRelayCommand(IBusyViewModel busyViewModel, Func<Task> execute)
+            : this(busyViewModel, execute, () => true)
+        {
+
+        }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public class TaskRelayCommand<T> : TaskBaseCommand
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskRelayCommand(Func<T, Task> execute, Func<T, bool> canExecute)
+            : this(default, execute, canExecute)
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="execute"></param>
+        public TaskRelayCommand(Func<T, Task> execute)
+            : this(default, execute, (x) => true)
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="busyViewModel"></param>
+        /// <param name="execute"></param>
+        /// <param name="canExecute"></param>
+        public TaskRelayCommand(IBusyViewModel busyViewModel, Func<T, Task> execute, Func<T, bool> canExecute)
+            : base(busyViewModel, (x) => execute((T)x), (x) => canExecute((T)x))
+        {
+
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="busyViewModel"></param>
+        /// <param name="execute"></param>
+        public TaskRelayCommand(IBusyViewModel busyViewModel, Func<T, Task> execute)
+            : this(busyViewModel, execute, (x) => true)
+        {
+
+        }
+    }
+}
diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/EasyMicroservices.UI.Core.Mvvm.csproj b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/EasyMicroservices.UI.Core.Mvvm.csproj
index 960a983..28a4e5b 100644
--- a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/EasyMicroservices.UI.Core.Mvvm.csproj
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/EasyMicroservices.UI.Core.Mvvm.csproj
@@ -5,7 +5,7 @@
     <Platforms>AnyCPU;x64;x86</Platforms>
     <Authors>EasyMicroservices</Authors>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-    <Version>0.0.0.3</Version>
+    <Version>0.0.0.4</Version>
     <Description>Model View View Model</Description>
     <Copyright>EasyMicroservices@gmail.com</Copyright>
     <PackageTags>mvvm,mvpvm,modelview,modelviewviewmodel</PackageTags>
diff --git a/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Interfaces/IBusyViewModel.cs b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Interfaces/IBusyViewModel.cs
new file mode 100644
index 0000000..b3cab0f
--- /dev/null
+++ b/src/CSharp/EasyMicroservices.UI.Core.Mvvm/Interfaces/IBusyViewModel.cs
@@ -0,0 +1,38 @@
+using System;
+using System.ComponentModel;
+using System.Threading.Tasks;
+
+namespace EasyMicroservices.UI.Core.Interfaces
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public interface IBusyViewModel : INotifyPropertyChanged
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        Action<bool> OnBusyChanged { get; set; }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        bool IsBusy { get; set; }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        void Busy();
+
+        /// <summary>
+        /// 
+        /// </summary>
+        void UnBusy();
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <returns></returns>
+        Task OnError(Exception exception);
+    }
+}