Do not implement props in ViewExtensionBase (DynamoDS#11350)

This changes the definition of ViewExtensionBase to use abstract rather
than virtual for the definition of required properties like Name and
UniqueId. The use of virtual was creating a backing field which was not
used in ViewExtensionBase and could not be assigned in the inheriting
class, making it pretty much useless.

Also the Dispose method is declared as abstract, as it was already
required to implement and having a default empty implementation could
lead developers to oversight the need to dispose resources in their
extension.

src/DocumentationBrowserViewExtension/DocumentationBrowserViewExtension.cs

@@ -1,12 +1,11 @@
-using Dynamo.Controls;
+using System;
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Controls;
 using Dynamo.DocumentationBrowser.Properties;
 using Dynamo.Logging;
 using Dynamo.ViewModels;
 using Dynamo.Wpf.Extensions;
-using System;
-using System.ComponentModel;
-using System.Windows;
-using System.Windows.Controls;
 
 namespace Dynamo.DocumentationBrowser
 {
@@ -24,12 +23,12 @@ public class DocumentationBrowserViewExtension : ViewExtensionBase, IViewExtensi
         /// <summary>
         /// Extension Name
         /// </summary>
-        public string Name => Properties.Resources.ExtensionName;
+        public override string Name => Properties.Resources.ExtensionName;
 
         /// <summary>
         /// GUID of the extension
         /// </summary>
-        public string UniqueId => "68B45FC0-0BD1-435C-BF28-B97CB03C71C8";
+        public override string UniqueId => "68B45FC0-0BD1-435C-BF28-B97CB03C71C8";
 
         public DocumentationBrowserViewExtension()
         {
@@ -50,12 +49,12 @@ internal void OnMessageLogged(ILogMessage msg)
 
         #region IViewExtension lifecycle
 
-        public void Startup(ViewStartupParams viewStartupParams)
+        public override void Startup(ViewStartupParams viewStartupParams)
         {
             // Do nothing for now
         }
 
-        public void Loaded(ViewLoadedParams viewLoadedParams)
+        public override void Loaded(ViewLoadedParams viewLoadedParams)
         {
             if (viewLoadedParams == null) throw new ArgumentNullException(nameof(viewLoadedParams));
 
@@ -86,11 +85,6 @@ private void MenuItemCheckHandler(object sender, RoutedEventArgs e)
             AddToSidebar(true);
         }
 
-        public void Shutdown()
-        {
-            // Do nothing for now
-        }
-
         protected virtual void Dispose(bool disposing)
         {
             // Cleanup
@@ -106,7 +100,7 @@ protected virtual void Dispose(bool disposing)
         /// <summary>
         /// Dispose function after extension is closed
         /// </summary>
-        public void Dispose()
+        public override void Dispose()
         {
             Dispose(true);
             GC.SuppressFinalize(this);

src/DynamoCoreWpf/Extensions/ViewExtensionBase.cs

@@ -17,20 +17,17 @@ public abstract class ViewExtensionBase : IViewExtension
         /// There may be multiple instances of the same type, but the application 
         /// will *not* allow two instances to coexist with the same id.
         /// </summary>
-        public virtual string UniqueId { get; }
+        public abstract string UniqueId { get; }
 
         /// <summary>
         /// A name for the extension instance.  This is used for more user-readable logging.
         /// </summary>
-        public virtual string Name { get; }
+        public abstract string Name { get; }
 
         /// <summary>
         /// Dispose method for the view extension.
         /// </summary>
-        public virtual void Dispose()
-        {
-
-        }
+        public abstract void Dispose();
 
         /// <summary>
         /// Action to be invoked when DynamoView begins to start up.  This is guaranteed to happen

src/WorkspaceDependencyViewExtension/WorkspaceDependencyViewExtension.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Linq;
 using System.Windows.Controls;
-using Dynamo.Controls;
 using Dynamo.Extensions;
 using Dynamo.Graph.Workspaces;
 using Dynamo.Logging;
@@ -32,7 +31,7 @@ internal WorkspaceDependencyView DependencyView
         /// <summary>
         /// Extension Name
         /// </summary>
-        public string Name
+        public override string Name
         {
             get
             {
@@ -43,7 +42,7 @@ public string Name
         /// <summary>
         /// GUID of the extension
         /// </summary>
-        public string UniqueId
+        public override string UniqueId
         {
             get
             {
@@ -54,7 +53,7 @@ public string UniqueId
         /// <summary>
         /// Dispose function after extension is closed
         /// </summary>
-        public void Dispose()
+        public override void Dispose()
         {
             DependencyView.Dispose();
         }
@@ -65,12 +64,7 @@ public void Ready(ReadyParams readyParams)
         {
         }
 
-        public void Shutdown()
-        {
-            // Do nothing for now
-        }
-
-        public void Startup(ViewStartupParams viewStartupParams)
+        public override void Startup(ViewStartupParams viewStartupParams)
         {
             pmExtension = viewStartupParams.ExtensionManager.Extensions.OfType<PackageManagerExtension>().FirstOrDefault();
         }
@@ -82,7 +76,7 @@ internal void OnMessageLogged(ILogMessage msg)
             this.MessageLogged?.Invoke(msg);
         }
 
-        public void Loaded(ViewLoadedParams viewLoadedParams)
+        public override void Loaded(ViewLoadedParams viewLoadedParams)
         {
             DependencyView = new WorkspaceDependencyView(this, viewLoadedParams);
             // when a package is loaded update the DependencyView