ExDM- Harmonize the code with the 01-DelegateEventsScript.md document #…

…404

- Updated sample code for event.
- UT 👍

ExDataManagement/FunctionalProgramming/FunctionalProgramming.UnitTest/AnonymousFunctionsUnitTest.cs

@@ -102,6 +102,7 @@ public void EventTestMethod()
       _newInstance.CurrentStateHandler.GoToIdle();
       Assert.AreEqual<State>(State.Idle, _currentState);
       //_newInstance.OnStateChanged(_newInstance, _newInstance.CurrentStateHandler.CurrentState);  //Error CS0070  The event 'AnonymousFunctions.OnStateChanged' can only appear on the left hand side of += or -= (except when used from within the type 'AnonymousFunctions')
+      //_newInstance.OnStateChanged = null;  //Error CS0070  The event 'AnonymousFunctions.OnStateChanged' can only appear on the left hand side of += or -= (except when used from within the type 'AnonymousFunctions')
     }
 
     #region Instrumentation

ExDataManagement/FunctionalProgramming/FunctionalProgramming/AnonymousFunctions.cs

@@ -10,6 +10,7 @@
 //_____________________________________________________________________________________________________________________________________
 
 using System;
+using System.ComponentModel;
 using System.Diagnostics;
 
 namespace TP.FunctionalProgramming
@@ -35,13 +36,13 @@ public class AnonymousFunctions
     internal delegate void CallBackTestDelegate(bool testResult);
 
     /// <summary>
-    /// Invoking this method the consistency of this state machine is checked. 
-    /// The result is transferred to the user through the <paramref name="testResult"/> delegate pointing 
-    /// out a method invoked to transfer the check result. While raising this delegate variable 
-    /// the null-conditional operator is not applied. Hence, this argument must not be null to prevent 
+    /// Invoking this method the consistency of this state machine is checked.
+    /// The result is transferred to the user through the <paramref name="testResult"/> delegate pointing
+    /// out a method invoked to transfer the check result. While raising this delegate variable
+    /// the null-conditional operator is not applied. Hence, this argument must not be null to prevent
     /// throwing an exception.
     /// </summary>
-    /// <param name="testResult">This parameter contains a delegate value pointing out a method invoked 
+    /// <param name="testResult">This parameter contains a delegate value pointing out a method invoked
     /// to transfer the check result. This argument must not be null to prevent throwing an exception.
     /// </param>
     /// <exception cref="NullReferenceException">exception thrown if the <paramref name="testResult"/> evaluates to null.
@@ -63,19 +64,27 @@ public AnonymousFunctions()
 
     public IStateHandler CurrentStateHandler { get; private set; }
 
-    public event EventHandler<State> OnStateChanged;
+    /// <summary>
+    /// event declarations sample code
+    /// </summary>
+    public event EventHandler<State> OnStateChanged = null;
 
     #endregion state machine context
 
     #region states implementation
 
     private abstract class StateHandlerBase : IStateHandler
     {
+      /// <summary>
+      /// constructor of the <see cref="StateHandlerBase"/>
+      /// </summary>
+      /// <param name="context">source of event notification</param>
       public StateHandlerBase(AnonymousFunctions context)
       {
         m_Context = context;
         m_Context.CurrentStateHandler = this;
-        m_Context.OnStateChanged?.Invoke(context, CurrentState);
+        m_Context.OnStateChanged?.Invoke(context, CurrentState); //Invocation of all the methods added to OnStateChanged, if any,
+                                                                 //CurrentState contains the event data transfered to users.
       }
 
       public abstract State CurrentState { get; }