add a uniquie event for plugin function execution

Pilz.Plugins.Advanced/PluginFeature.cs

@@ -1,7 +1,17 @@
-namespace Pilz.Plugins.Advanced;
+using System.Reflection.Metadata;
+
+namespace Pilz.Plugins.Advanced;
 
 public abstract class PluginFeature
 {
+    /// <summary>
+    /// Fires when the plugin feature gets used.
+    /// <br/>- For <see cref="PluginFunction"/> this fires on <see cref="PluginFunction.ExecuteFunction(PluginFunctionParameter?)"/>.
+    /// <br/>- For <see cref="T:PluginModule"/> this fires on <see cref="T:PluginModule.CreateNewUI(PluginFunctionParameter?)"/>.
+    /// <br/>- For any other custom feature implementation this may variate.
+    /// </summary>
+    public static event PluginFeatureExecuteEventHandler? OnExecute;
+
     /// <summary>
     /// The type of the feature defines where the feature get integrated.
     /// </summary>
@@ -50,4 +60,49 @@ public abstract class PluginFeature
     {
         return $"{featureType}:{identifier}";
     }
+
+    /// <summary>
+    /// Fires the <see cref="OnExecute"/> event with the status <see cref="PluginFeatureExecuteEventType.PostEvent"/>.
+    /// </summary>
+    /// <param name="params">The present <see cref="PluginFunctionParameter"/>.</param>
+    /// <param name="result">The resulting object that will be returned.</param>
+    /// <returns>Returns true if the original function should be executed.</returns>
+    protected bool OnPreExecute(PluginFunctionParameter? @params, ref object? result)
+    {
+        if (OnExecute != null)
+        {
+            var args = new PluginFeatureExecuteEventArgs(PluginFeatureExecuteEventType.PreEvent, @params);
+
+            OnExecute.Invoke(this, args);
+
+            if (args.Handled)
+            {
+                result = args.Result;
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    /// Fires the <see cref="OnExecute"/> event with the status <see cref="PluginFeatureExecuteEventType.PostEvent"/>.
+    /// </summary>
+    /// <param name="params">The present <see cref="PluginFunctionParameter"/>.</param>
+    /// <param name="result">The resulting object that will be returned.</param>
+    protected void OnPostExecute(PluginFunctionParameter? @params, ref object? result)
+    {
+        if (OnExecute != null)
+        {
+            var args = new PluginFeatureExecuteEventArgs(PluginFeatureExecuteEventType.PostEvent, @params)
+            {
+                Result = result
+            };
+
+            OnExecute.Invoke(this, args);
+
+            if (args.Handled)
+                result = args.Result;
+        }
+    }
 }