[+] Some comments

[+] EventMediator Unsubscribe CactuseSecurity#3145

Author: SolidProgramming

roles/lib/files/FWO.Services/EventMediator/EventMediator.cs

@@ -1,25 +1,43 @@
-using FWO.Data;
 using FWO.Services.EventMediator.Interfaces;
 
 namespace FWO.Services.EventMediator;
 
 public class EventMediator : IEventMediator
 {
-    private readonly Dictionary<Type, List<Action<IEvent>>> _handlers = [];
+    private readonly Dictionary<Type, Dictionary<string, List<Action<IEvent>>>> _handlers = [];
 
-    public void Subscribe<TEvent>(Action<TEvent> handler) where TEvent : class, IEvent
+    /// <summary>
+    /// Adds the handler as an invokeable action.
+    /// </summary>
+    /// <typeparam name="TEvent"></typeparam>
+    /// <param name="name"></param>
+    /// <param name="handler"></param>
+    public void Subscribe<TEvent>(string name, Action<TEvent> handler) where TEvent : class, IEvent
     {
         if(!_handlers.ContainsKey(typeof(TEvent)))
         {
             _handlers[typeof(TEvent)] = [];
         }
 
-        _handlers[typeof(TEvent)].Add(e => handler((TEvent)e));
+        if(!_handlers[typeof(TEvent)].TryGetValue(name, out List<Action<IEvent>>? value))
+        {
+            value = [];
+            _handlers[typeof(TEvent)][name] = value;
+        }
+
+        value.Add(e => handler((TEvent)e));
     }
 
-    public void Publish<TEvent>(TEvent @event)  where TEvent : class, IEvent
+    /// <summary>
+    /// If matching subscription handler was found it will be invoked.
+    /// </summary>
+    /// <typeparam name="TEvent"></typeparam>
+    /// <param name="name"></param>
+    /// <param name="event"></param>
+    public void Publish<TEvent>(string name, TEvent @event) where TEvent : class, IEvent
     {
-        if(_handlers.TryGetValue(typeof(TEvent), out List<Action<IEvent>>? handlers))
+        if(_handlers.TryGetValue(typeof(TEvent), out Dictionary<string, List<Action<IEvent>>>? actions) 
+            && actions.TryGetValue(name, out List<Action<IEvent>>? handlers))
         {
             foreach(Action<IEvent> handler in handlers)
             {
@@ -28,9 +46,20 @@ public void Publish<TEvent>(TEvent @event)  where TEvent : class, IEvent
         }
     }
 
-    public void Unsubscribe<TEvent>(TEvent @event)
+    /// <summary>
+    /// Unsubscribe of ALL events of the given type matching the name.
+    /// </summary>
+    /// <typeparam name="TEvent"></typeparam>
+    /// <param name="event"></param>
+    /// <returns>True/False if remove was successfull</returns>
+    public bool Unsubscribe<TEvent>(string name) where TEvent : class, IEvent
     {
+        if(_handlers.ContainsKey(typeof(TEvent)))
+        {
+           return _handlers.Remove(typeof(TEvent));
+        }
 
+        return false;
     }
 }
 

roles/lib/files/FWO.Services/EventMediator/Interfaces/IEventMediator.cs

@@ -2,7 +2,8 @@ namespace FWO.Services.EventMediator.Interfaces;
 
 public interface IEventMediator
 {
-    void Subscribe<TEvent>(Action<TEvent> handler) where TEvent : class, IEvent;
-    void Publish<TEvent>(TEvent @event) where TEvent : class, IEvent;
+    void Subscribe<TEvent>(string name, Action<TEvent> handler) where TEvent : class, IEvent;
+    void Publish<TEvent>(string name, TEvent @event) where TEvent : class, IEvent;
+    bool Unsubscribe<TEvent>(string name) where TEvent : class, IEvent;
 }
 

roles/ui/files/FWO.UI/Pages/NetworkModelling/EditAppRole.razor

@@ -296,7 +296,7 @@
                 workInProgress = true;
                 await AppRoleHandler.InitAppRole(newArea);
 
-                EventMediator.Publish<CollectionChangedEvent>(OnCollectionChanged);
+                EventMediator.Publish<CollectionChangedEvent>(nameof(EditAppRole), OnCollectionChanged);
 
                 workInProgress = false;
             }

roles/ui/files/FWO.UI/Shared/OrderByDropdown.razor

@@ -8,6 +8,7 @@
 @using System.Net
 @using System.Reflection
 @inject IEventMediator EventMediator
+@implements IDisposable
 
 @typeparam TCollectionItem
 
@@ -118,7 +119,8 @@
                 CssClass = "";
             }
 
-            EventMediator.Subscribe<CollectionChangedEvent>(new Action<CollectionChangedEvent>(_ => ReorderCollection()));
+            EventMediator.Subscribe<CollectionChangedEvent>(nameof(Pages.NetworkModelling.EditAppRole), 
+                new Action<CollectionChangedEvent>(_ => ReorderCollection()));
 
             initialized = true;
         }
@@ -195,7 +197,7 @@
         {
             throw new InvalidOperationException(); 
         }
-        
+
         MemberExpression propertyAccess = Expression.Property(param, propertyInfo);
         UnaryExpression converted = Expression.Convert(propertyAccess, typeof(object));
 
@@ -239,4 +241,10 @@
                 throw new NotImplementedException();
         }
     }
+
+
+    public void Dispose()
+    {
+        EventMediator.Unsubscribe<CollectionChangedEvent>(nameof(Pages.NetworkModelling.EditAppRole));
+    }
 }