Marked unused event handlers as [Obsolete]

JeremyCaney · JeremyCaney · commit 3cd74658499f · 2020-04-17T17:01:49.000-07:00
For a decade, we've continued to maintain the `DeleteEvent`, `MoveEvent`, and `RenameEvent` on `ITopicRepository` and its predecessors. No implementation has actually ever actually used them, however. There may be a good use case for these (I can imagine several) but the fact that we have never ended up utilizing them makes their value unconvincing.

Further, they're not currently covered by unit tests, which means we're not confident they even work as expected.

Ultimately, if we want to implement events for a project, we likely want far more extensive event coverage (e.g., for other services, for before and after states, &amp;c.) and should revisit this as a more deliberate effort.
diff --git a/OnTopic/Repositories/DeleteEventArgs.cs b/OnTopic/Repositories/DeleteEventArgs.cs
@@ -13,6 +13,7 @@ namespace OnTopic.Repositories {
   /// <summary>
   ///   The DeleteEventArgs class defines an event argument type specific to deletion events
   /// </summary>
+  [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
   public class DeleteEventArgs : EventArgs {
 
     /*==========================================================================================================================
diff --git a/OnTopic/Repositories/ITopicRepository.cs b/OnTopic/Repositories/ITopicRepository.cs
@@ -22,16 +22,19 @@ public interface ITopicRepository {
     /// <summary>
     ///   Instantiates the <see cref="DeleteEventArgs"/> event handler.
     /// </summary>
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     event EventHandler<DeleteEventArgs> DeleteEvent;
 
     /// <summary>
     ///   Instantiates the <see cref="MoveEventArgs"/> event handler.
     /// </summary>
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     event EventHandler<MoveEventArgs> MoveEvent;
 
     /// <summary>
     ///   Instantiates the <see cref="RenameEventArgs"/> event handler.
     /// </summary>
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     event EventHandler<RenameEventArgs> RenameEvent;
 
     /*==========================================================================================================================
diff --git a/OnTopic/Repositories/MoveEventArgs.cs b/OnTopic/Repositories/MoveEventArgs.cs
@@ -17,6 +17,7 @@ namespace OnTopic.Repositories {
   /// <remarks>
   ///   Allows tracking of the source and destination topics.
   /// </remarks>
+  [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
   public class MoveEventArgs : EventArgs {
 
     /*==========================================================================================================================
diff --git a/OnTopic/Repositories/RenameEventArgs.cs b/OnTopic/Repositories/RenameEventArgs.cs
@@ -13,6 +13,7 @@ namespace OnTopic.Repositories {
   /// <summary>
   ///   The RenameEventArgs object defines an event argument type specific to rename events.
   /// </summary>
+  [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
   public class RenameEventArgs : EventArgs {
 
     /*==========================================================================================================================
diff --git a/OnTopic/Repositories/TopicRepositoryBase.cs b/OnTopic/Repositories/TopicRepositoryBase.cs
@@ -15,6 +15,8 @@
 using System.Linq;
 using OnTopic.Collections;
 
+#pragma warning disable CS0618 // Type or member is obsolete; used to hide known deprecation of events until v5.0.0
+
 namespace OnTopic.Repositories {
 
   /*============================================================================================================================
@@ -34,12 +36,15 @@ public abstract class TopicRepositoryBase : ITopicRepository {
     | EVENT HANDLERS
     \-------------------------------------------------------------------------------------------------------------------------*/
     /// <inheritdoc />
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     public event EventHandler<DeleteEventArgs>? DeleteEvent;
 
     /// <inheritdoc />
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     public event EventHandler<MoveEventArgs>? MoveEvent;
 
     /// <inheritdoc />
+    [Obsolete("The TopicRepository events will be removed in OnTopic Library 5.0.", false)]
     public event EventHandler<RenameEventArgs>? RenameEvent;
 
     /*==========================================================================================================================
@@ -434,4 +439,6 @@ protected IEnumerable<AttributeDescriptor> GetUnmatchedAttributes(Topic topic) {
     }
 
   } //Class
-} //Namespace
+} //Namespace
+
+#pragma warning restore CS0618 // Type or member is obsolete
