Add post-add event to collection js

Resources/doc/collection-helper.md

@@ -155,6 +155,21 @@ Properties provided on the event object:
 - `insertBefore`: if set by an event listener, the row will be inserted before this dom
                   element.
 
+### infinite_collection_added
+
+This event is fired when a new item has been added to a collection. It allows 
+functionality to work with the post-add dom without the need to add dom mutate observers.
+
+Properties provided on the event object:
+
+- `collection`: The window.infinite.Collection instance
+- `$triggeredPrototype`: this is the dom element that triggered the adding of an item to
+                         the collection. In the case of a normal collection type, the
+                         prototype will be the add button. In the case of the
+                         Polycollection, the prototype will be one of the prototype
+                         buttons.
+- `$row`: the jQuery wrapped DOM elements that was added to the collection.
+
 ### infinite_collection_remove
 
 This event is fired before a row is to be removed from the DOM. This event does not fire

Resources/public/js/collections.js

@@ -87,17 +87,24 @@
             var html = this._getPrototypeHtml($prototype, this.internalCount++),
                 $row = $($.parseHTML(html, document, this.options.keepScripts));
 
-            var event = this._createEvent('infinite_collection_add');
-            event.$triggeredPrototype = $prototype;
-            event.$row = $row;
-            event.insertBefore = null;
-            this.$collection.trigger(event);
+            var addEvent = this._createEvent('infinite_collection_add');
+            addEvent.$triggeredPrototype = $prototype;
+            addEvent.$row = $row;
+            addEvent.insertBefore = null;
 
-            if (!event.isDefaultPrevented()) {
+            this.$collection.trigger(addEvent);
+
+            var addedEvent = this._createEvent('infinite_collection_added');
+            addedEvent.$triggeredPrototype = $prototype;
+            addedEvent.$row = $row;
+
+            if (!addEvent.isDefaultPrevented()) {
                 if (event.insertBefore) {
                     $row.insertBefore(event.insertBefore);
+                    this.$collection.trigger(addedEvent);
                 } else {
                     this.$collection.append($row);
+                    this.$collection.trigger(addedEvent);
                 }
 
                 return $row;