Option to prevent backbone from adding new models to a collection (update only)

Prevents upcoming/calendar from blowing up when

src/UI/Calendar/CalendarView.js

@@ -16,7 +16,7 @@ define(
 
         return Marionette.ItemView.extend({
             initialize: function () {
-                this.collection = new CalendarCollection().bindSignalR();
+                this.collection = new CalendarCollection().bindSignalR({ updateOnly: true });
                 this.listenTo(this.collection, 'change', this._reloadCalendarEvents);
             },
             render    : function () {

src/UI/Calendar/UpcomingCollectionView.js

@@ -11,14 +11,8 @@ define(
             itemView: UpcomingItemView,
 
             initialize: function () {
-                this.collection = new UpcomingCollection().bindSignalR();
+                this.collection = new UpcomingCollection().bindSignalR({ updateOnly: true });
                 this.collection.fetch();
-
-                this.listenTo(this.collection, 'change', this._refresh);
-            },
-
-            _refresh: function () {
-                this.render();
             }
         });
     });

src/UI/Calendar/UpcomingItemView.js

@@ -22,6 +22,8 @@ define(
                 this.model.set({
                     end: end.toISOString()
                 });
+
+                this.listenTo(this.model, 'change', this.render);
             },
 
             _showEpisodeDetails: function () {

src/UI/Mixins/backbone.signalr.mixin.js

@@ -8,9 +8,10 @@ define(
     ], function (vent, _, Backbone) {
 
         _.extend(Backbone.Collection.prototype, {
-            bindSignalR: function () {
+            bindSignalR: function (bindOptions) {
 
                 var collection = this;
+                bindOptions = bindOptions || {};
 
                 var processMessage = function (options) {
 
@@ -22,6 +23,12 @@ define(
                     }
 
                     var model = new collection.model(options.resource, {parse: true});
+
+                    //updateOnly will prevent the collection from adding a new item
+                    if (bindOptions.updateOnly && !collection.get(model.get('id'))) {
+                        return;
+                    }
+
                     collection.add(model, {merge: true});
                     console.log(options.action + ': {0}}'.format(options.resource));
                 };