Register PreviewHub in composer

It actually updates now \o/

src/Umbraco.Web.BackOffice/SignalR/IPreviewHub.cs

@@ -1,4 +1,5 @@
-using Microsoft.AspNetCore.SignalR;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.SignalR;
 
 namespace Umbraco.Web.BackOffice.SignalR
 {
@@ -7,7 +8,7 @@ namespace Umbraco.Web.BackOffice.SignalR
         // define methods implemented by client
         // ReSharper disable InconsistentNaming
 
-        void refreshed(int id);
+        Task refreshed(int id);
 
         // ReSharper restore InconsistentNaming
     }

src/Umbraco.Web.BackOffice/SignalR/PreviewHubComponent.cs

@@ -33,7 +33,7 @@ namespace Umbraco.Web.BackOffice.SignalR
             ContentCacheRefresher.CacheUpdated -= HandleCacheUpdated;
         }
 
-        private void HandleCacheUpdated(ContentCacheRefresher sender, CacheRefresherEventArgs args)
+        private async void HandleCacheUpdated(ContentCacheRefresher sender, CacheRefresherEventArgs args)
         {
             if (args.MessageType != MessageType.RefreshByPayload) return;
             var payloads = (ContentCacheRefresher.JsonPayload[])args.MessageObject;
@@ -41,7 +41,7 @@ namespace Umbraco.Web.BackOffice.SignalR
             foreach (var payload in payloads)
             {
                 var id = payload.Id; // keep it simple for now, ignore ChangeTypes
-                hubContextInstance.Clients.All.refreshed(id);
+                await hubContextInstance.Clients.All.refreshed(id);
             }
         }
     }

src/Umbraco.Web.BackOffice/SignalR/PreviewHubComposer.cs

@@ -0,0 +1,17 @@
+using Umbraco.Core;
+using Umbraco.Core.Composing;
+using Umbraco.Web.BackOffice.SignalR;
+
+namespace Umbraco.Web.SignalR
+{
+    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
+    public class PreviewHubComposer : ComponentComposer<PreviewHubComponent>, ICoreComposer
+    {
+        public override void Compose(Composition composition)
+        {
+            base.Compose(composition);
+
+            // composition.RegisterUnique(_ => GlobalHost.ConnectionManager.GetHubContext<PreviewHub, IPreviewHub>());
+        }
+    }
+}

src/Umbraco.Web.UI.Client/src/preview/preview.controller.js

@@ -5,7 +5,7 @@
 
 var app = angular.module("umbraco.preview", ['umbraco.resources', 'umbraco.services'])
 
-    .controller("previewController", function ($scope, $window, $location) {
+    .controller("previewController", function ($scope, $window, $location, umbRequestHelper) {
 
         $scope.currentCulture = { iso: '', title: '...', icon: 'icon-loading' }
         var cultures = [];
@@ -46,7 +46,8 @@ var app = angular.module("umbraco.preview", ['umbraco.resources', 'umbraco.servi
         function configureSignalR(iframe) {
             // signalr hub
             var previewHub = new signalR.HubConnectionBuilder()
-                .withUrl("/umbraco/previewHub")
+                .withUrl("/umbraco/PreviewHub")
+                .withAutomaticReconnect()
                 .build();
 
             // visibility tracking