feat: general improvements and minor bugs

Author: ReneSchwarzer

src/WebExpress.WebCore/WebTask/ITaskManager.cs

@@ -9,6 +9,11 @@ namespace WebExpress.WebCore.WebTask
     /// </summary>
     public interface ITaskManager : IComponentManager
     {
+        /// <summary>
+        /// Event is triggered when a task's changes.
+        /// </summary>
+        event EventHandler<TaskEventArgs> TaskChanged;
+
         /// <summary>
         /// Returns the collection of tasks.
         /// </summary>

src/WebExpress.WebCore/WebTask/Task.cs

@@ -11,6 +11,7 @@ namespace WebExpress.WebCore.WebTask
     public class Task : ITask
     {
         private int _progress;
+        private string _message;
 
         /// <summary>
         /// Event is triggered when the task is executed.
@@ -22,6 +23,16 @@ public class Task : ITask
         /// </summary>
         public event EventHandler<TaskEventArgs> Finish;
 
+        /// <summary>
+        /// Event is triggered when the progress changes.
+        /// </summary>
+        public event EventHandler<TaskEventArgs> ProgressChanged;
+
+        /// <summary>
+        /// Event is triggered when the message changes.
+        /// </summary>
+        public event EventHandler<TaskEventArgs> MessageChanged;
+
         /// <summary>
         /// Returns the id of the task.
         /// </summary>
@@ -47,14 +58,35 @@ public class Task : ITask
         /// </summary>
         public int Progress
         {
-            get => _progress;
-            set => _progress = Math.Min(value, 100);
+            get { return _progress; }
+            set
+            {
+                var newValue = Math.Min(value, 100);
+                if (_progress != newValue)
+                {
+                    _progress = newValue;
+                    // trigger progress changed event
+                    OnProgressChanged();
+                }
+            }
         }
 
         /// <summary>
         /// Returns or sets a message that provides information about the processing.
         /// </summary>
-        public string Message { get; set; }
+        public string Message
+        {
+            get { return _message; }
+            set
+            {
+                if (_message != value)
+                {
+                    _message = value;
+                    // trigger message changed event
+                    OnMessageChanged();
+                }
+            }
+        }
 
         /// <summary>
         /// Initializes a new instance of the class.
@@ -72,15 +104,31 @@ public Task(string id, params object[] args)
         /// </summary>
         protected virtual void OnProcess()
         {
-            Process?.Invoke(this, new TaskEventArgs());
+            Process?.Invoke(this, new TaskEventArgs(this, 0));
         }
 
         /// <summary>
         /// Triggered when the task is complete.
         /// </summary>
         protected virtual void OnFinish()
         {
-            Finish?.Invoke(this, new TaskEventArgs());
+            Finish?.Invoke(this, new TaskEventArgs(this, 100));
+        }
+
+        /// <summary>
+        /// Triggered when the progress changes.
+        /// </summary>
+        protected virtual void OnProgressChanged()
+        {
+            ProgressChanged?.Invoke(this, new TaskEventArgs(this, Progress));
+        }
+
+        /// <summary>
+        /// Triggered when the message changes.
+        /// </summary>
+        protected virtual void OnMessageChanged()
+        {
+            MessageChanged?.Invoke(this, new TaskEventArgs(this, Progress, Message));
         }
 
         /// <summary>

src/WebExpress.WebCore/WebTask/TaskEventArgs.cs

@@ -7,5 +7,32 @@ namespace WebExpress.WebCore.WebTask
     /// </summary>
     public class TaskEventArgs : EventArgs
     {
+        /// <summary>
+        /// Returns the related task.
+        /// </summary>
+        public ITask Task { get; }
+
+        /// <summary>
+        /// Returns the current progress (if relevant).
+        /// </summary>
+        public int Progress { get; }
+
+        /// <summary>
+        /// Returns the current or new message (if relevant).
+        /// </summary>
+        public string Message { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the class.
+        /// </summary>
+        /// <param name="task">The related task.</param>
+        /// <param name="progress">The current progress.</param>
+        /// <param name="message">The current or new message.</param>
+        public TaskEventArgs(ITask task, int progress = 0, string message = null)
+        {
+            Task = task;
+            Progress = progress;
+            Message = message;
+        }
     }
 }

src/WebExpress.WebCore/WebTask/TaskManager.cs

@@ -16,6 +16,11 @@ public class TaskManager : ITaskManager, ISystemComponent
         private readonly IHttpServerContext _httpServerContext;
         private readonly TaskDictionary _dictionary = [];
 
+        /// <summary>
+        /// Event is triggered when a task's changes.
+        /// </summary>
+        public event EventHandler<TaskEventArgs> TaskChanged;
+
         /// <summary>
         /// Returns the collection of tasks.
         /// </summary>
@@ -79,6 +84,10 @@ public ITask CreateTask(string id, params object[] args)
             }
 
             var task = ComponentActivator.CreateInstance<Task>(_httpServerContext, _componentHub, [id, args]);
+
+            // register events for the newly created task
+            task.ProgressChanged += OnTaskChanged;
+
             _dictionary.Add(key, task);
 
             return task;
@@ -115,6 +124,10 @@ public ITask CreateTask<TTask>(string id, EventHandler<TaskEventArgs> handler, p
             }
 
             var task = ComponentActivator.CreateInstance<TTask>(_httpServerContext, _componentHub, [id, args]);
+
+            // register events for the newly created task
+            task.ProgressChanged += OnTaskChanged;
+
             _dictionary.Add(key, task);
 
             task.Process += handler;
@@ -130,6 +143,12 @@ public void RemoveTask(ITask task)
         {
             var key = task?.Id.ToLower();
 
+            if (_dictionary.TryGetValue(key, out var storedTask) && storedTask is Task t)
+            {
+                // unregister events to prevent memory leaks
+                t.ProgressChanged -= OnTaskChanged;
+            }
+
             _dictionary.Remove(key);
         }
 
@@ -140,5 +159,15 @@ public void Dispose()
         {
             GC.SuppressFinalize(this);
         }
+
+        /// <summary>
+        /// Handles the changed event from a task.
+        /// </summary>
+        /// <param name="sender">The sender.</param>
+        /// <param name="e">The event arguments.</param>
+        private void OnTaskChanged(object sender, TaskEventArgs e)
+        {
+            TaskChanged?.Invoke(sender, e);
+        }
     }
 }