From ed37b84b3b3825a88b4d3c65eafc0342cea71751 Mon Sep 17 00:00:00 2001
From: Shannon <sdeminick@gmail.com>
Date: Thu, 24 Nov 2016 11:20:01 +0100
Subject: [PATCH] makes public the WeightedPluginAttribute, uses this for
 resolving the startup handlers so they could be sorted, adds special event to
 allow modifying the startup handlers.

---
 .../ApplicationEventsEventArgs.cs             | 15 +++++++
 .../ApplicationEventsResolver.cs              | 45 +++++++++++++++----
 .../WeightedPluginAttribute.cs                |  2 +-
 src/Umbraco.Core/Umbraco.Core.csproj          |  1 +
 4 files changed, 53 insertions(+), 10 deletions(-)
 create mode 100644 src/Umbraco.Core/ObjectResolution/ApplicationEventsEventArgs.cs

diff --git a/src/Umbraco.Core/ObjectResolution/ApplicationEventsEventArgs.cs b/src/Umbraco.Core/ObjectResolution/ApplicationEventsEventArgs.cs
new file mode 100644
index 0000000000..a459fc7268
--- /dev/null
+++ b/src/Umbraco.Core/ObjectResolution/ApplicationEventsEventArgs.cs
@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+
+namespace Umbraco.Core.ObjectResolution
+{
+    public class ApplicationEventsEventArgs : EventArgs
+    {
+        public List<IApplicationEventHandler> Handlers { get; private set; }
+
+        public ApplicationEventsEventArgs(List<IApplicationEventHandler> handlers)
+        {
+            Handlers = handlers;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/ObjectResolution/ApplicationEventsResolver.cs b/src/Umbraco.Core/ObjectResolution/ApplicationEventsResolver.cs
index 78c8f483f2..be94d7a3b9 100644
--- a/src/Umbraco.Core/ObjectResolution/ApplicationEventsResolver.cs
+++ b/src/Umbraco.Core/ObjectResolution/ApplicationEventsResolver.cs
@@ -13,7 +13,7 @@ namespace Umbraco.Core.ObjectResolution
 	/// <remarks>
 	/// This is disposable because after the app has started it should be disposed to release any memory being occupied by instances.
 	/// </remarks>
-    internal  sealed class ApplicationEventsResolver : ManyObjectsResolverBase<ApplicationEventsResolver, IApplicationEventHandler>, IDisposable
+    public sealed class ApplicationEventsResolver : ManyObjectsResolverBase<ApplicationEventsResolver, IApplicationEventHandler>, IDisposable
 	{
 
 	    private readonly LegacyStartupHandlerResolver _legacyResolver;
@@ -30,7 +30,7 @@ namespace Umbraco.Core.ObjectResolution
             //create the legacy resolver and only include the legacy types
 	        _legacyResolver = new LegacyStartupHandlerResolver(
                 serviceProvider, logger,
-	            applicationEventHandlers.Where(x => !TypeHelper.IsTypeAssignableFrom<IApplicationEventHandler>(x)));
+	            applicationEventHandlers.Where(x => TypeHelper.IsTypeAssignableFrom<IApplicationEventHandler>(x) == false));
 		}
 
         /// <summary>
@@ -42,14 +42,34 @@ namespace Umbraco.Core.ObjectResolution
             get { return base.InstanceTypes.Where(TypeHelper.IsTypeAssignableFrom<IApplicationEventHandler>); }
         }
 
-	    /// <summary>
-		/// Gets the <see cref="IApplicationEventHandler"/> implementations.
-		/// </summary>
-		public IEnumerable<IApplicationEventHandler> ApplicationEventHandlers
+	    private List<IApplicationEventHandler> _orderedAndFiltered;
+
+        /// <summary>
+        /// Gets the <see cref="IApplicationEventHandler"/> implementations.
+        /// </summary>
+        public IEnumerable<IApplicationEventHandler> ApplicationEventHandlers
 		{
-            get { return Values; }
+	        get
+	        {
+	            if (_orderedAndFiltered == null)
+	            {
+                    _orderedAndFiltered = GetSortedValues().ToList();
+
+                    //raise event so the collection can be modified
+                    OnCollectionResolved(new ApplicationEventsEventArgs(_orderedAndFiltered));
+                }
+	            return _orderedAndFiltered;
+	        }
 		}
 
+	    public event EventHandler<ApplicationEventsEventArgs> CollectionResolved;
+
+        private void OnCollectionResolved(ApplicationEventsEventArgs e)
+        {
+            var handler = CollectionResolved;
+            if (handler != null) handler(this, e);
+        }
+        
         /// <summary>
         /// Create instances of all of the legacy startup handlers
         /// </summary>
@@ -146,7 +166,14 @@ namespace Umbraco.Core.ObjectResolution
 	    {
             _legacyResolver.Dispose();
             ResetCollections();
+            _orderedAndFiltered.Clear();
+	        _orderedAndFiltered = null;
+
+            //Clear event handlers
+	        CollectionResolved = null;
+
 	    }
-        
-	}
+
+	    
+    }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/ObjectResolution/WeightedPluginAttribute.cs b/src/Umbraco.Core/ObjectResolution/WeightedPluginAttribute.cs
index 323142bd4c..69c763ed50 100644
--- a/src/Umbraco.Core/ObjectResolution/WeightedPluginAttribute.cs
+++ b/src/Umbraco.Core/ObjectResolution/WeightedPluginAttribute.cs
@@ -6,7 +6,7 @@ namespace Umbraco.Core.ObjectResolution
 	/// Indicates the relative weight of a resolved object type.
 	/// </summary>
 	[AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
-	internal class WeightedPluginAttribute : Attribute
+	public class WeightedPluginAttribute : Attribute
 	{
 		/// <summary>
 		/// Initializes a new instance of the <see cref="WeightedPluginAttribute"/> class with a weight.
diff --git a/src/Umbraco.Core/Umbraco.Core.csproj b/src/Umbraco.Core/Umbraco.Core.csproj
index 7a4c4f2363..3c58503b57 100644
--- a/src/Umbraco.Core/Umbraco.Core.csproj
+++ b/src/Umbraco.Core/Umbraco.Core.csproj
@@ -415,6 +415,7 @@
     <Compile Include="Models\UmbracoDomain.cs" />
     <Compile Include="Models\DoNotCloneAttribute.cs" />
     <Compile Include="Models\IDomain.cs" />
+    <Compile Include="ObjectResolution\ApplicationEventsEventArgs.cs" />
     <Compile Include="Persistence\BulkDataReader.cs" />
     <Compile Include="Persistence\DatabaseNodeLockExtensions.cs" />
     <Compile Include="Persistence\Factories\ExternalLoginFactory.cs" />