U4-8286 Add OWIN startup events to the UmbracoDefaultOwinStartup class

src/Umbraco.Core/UmbracoApplicationBase.cs

@@ -72,6 +72,11 @@ namespace Umbraco.Core
         /// <summary>
         /// Override init and raise the event
         /// </summary>
+        /// <remarks>
+        /// DID YOU KNOW? The Global.asax Init call is the thing that initializes all of the httpmodules, ties up a bunch of stuff with IIS, etc...
+        /// Therefore, since OWIN is an HttpModule when running in IIS/ASP.Net the OWIN startup is not executed until this method fires and by that
+        /// time, Umbraco has performed it's bootup sequence.
+        /// </remarks>
         public override void Init()
         {
             base.Init();

src/Umbraco.Web/OwinMiddlewareConfiguredEventArgs.cs

@@ -0,0 +1,15 @@
+using System;
+using Owin;
+
+namespace Umbraco.Web
+{
+    public class OwinMiddlewareConfiguredEventArgs : EventArgs
+    {
+        public OwinMiddlewareConfiguredEventArgs(IAppBuilder appBuilder)
+        {
+            AppBuilder = appBuilder;
+        }
+
+        public IAppBuilder AppBuilder { get; private set; }
+    }
+}

src/Umbraco.Web/Security/Identity/AppBuilderExtensions.cs

@@ -24,10 +24,31 @@ namespace Umbraco.Web.Security.Identity
 {
     public static class AppBuilderExtensions
     {
+        /// <summary>
+        /// Called at the end of configuring middleware
+        /// </summary>
+        /// <param name="app"></param>
+        /// <remarks>
+        /// This could be used for something else in the future - maybe to inform Umbraco that middleware is done/ready, but for
+        /// now this is used to raise the custom event
+        /// 
+        /// This is an extension method in case developer entirely replace the UmbracoDefaultOwinStartup class, in which case they will
+        /// need to ensure they call this extension method in their startup class.
+        /// 
+        /// TODO: Move this method in v8, it doesn't belong in this namespace/extension class
+        /// </remarks>
+        public static void FinalizeMiddlewareConfiguration(this IAppBuilder app)
+        {
+            UmbracoDefaultOwinStartup.OnMiddlewareConfigured(new OwinMiddlewareConfiguredEventArgs(app));
+        }
+
         /// <summary>
         /// Sets the OWIN logger to use Umbraco's logging system
         /// </summary>
         /// <param name="app"></param>
+        /// <remarks>
+        /// TODO: Move this method in v8, it doesn't belong in this namespace/extension class
+        /// </remarks>
         public static void SetUmbracoLoggerFactory(this IAppBuilder app)
         {
             app.SetLoggerFactory(new OwinLoggerFactory());

src/Umbraco.Web/Umbraco.Web.csproj

@@ -349,6 +349,7 @@
     <Compile Include="Mvc\ModelBindingException.cs" />
     <Compile Include="Mvc\RenderIndexActionSelectorAttribute.cs" />
     <Compile Include="Mvc\ValidateMvcAngularAntiForgeryTokenAttribute.cs" />
+    <Compile Include="OwinMiddlewareConfiguredEventArgs.cs" />
     <Compile Include="PropertyEditors\DatePreValueEditor.cs" />
     <Compile Include="PropertyEditors\DecimalPropertyEditor.cs" />
     <Compile Include="PropertyEditors\ValueConverters\ImageCropDataSetConverter.cs" />

src/Umbraco.Web/UmbracoDefaultOwinStartup.cs

@@ -1,4 +1,5 @@
-using System.Web;
+using System;
+using System.Web;
 using Microsoft.Owin;
 using Microsoft.Owin.Extensions;
 using Microsoft.Owin.Logging;
@@ -59,12 +60,24 @@ namespace Umbraco.Web
             app
                 .UseUmbracoBackOfficeCookieAuthentication(ApplicationContext, PipelineStage.Authenticate)
                 .UseUmbracoBackOfficeExternalCookieAuthentication(ApplicationContext, PipelineStage.Authenticate)
-                .UseUmbracoPreviewAuthentication(ApplicationContext, PipelineStage.Authorize);
+                .UseUmbracoPreviewAuthentication(ApplicationContext, PipelineStage.Authorize)
+                .FinalizeMiddlewareConfiguration();
         }
 
+        /// <summary>
+        /// Raised when the middelware has been configured
+        /// </summary>
+        public static event EventHandler<OwinMiddlewareConfiguredEventArgs> MiddlewareConfigured;
+
         protected virtual ApplicationContext ApplicationContext
         {
             get { return ApplicationContext.Current; }
         }
+
+        internal static void OnMiddlewareConfigured(OwinMiddlewareConfiguredEventArgs args)
+        {
+            var handler = MiddlewareConfigured;
+            if (handler != null) handler(null, args);
+        }
     }
 }