Changed parent/child api widgets

IPython/html/static/notebook/js/widget.js

@@ -211,7 +211,7 b' define(["../../components/underscore/underscore-min.js",'
                     var parent_model = parent_comm.model;
                     var parent_view = parent_model.views[cell_index];
                     if (parent_view.display_child != undefined) {
-                        parent_view.display_child(view.$el);
+                        parent_view.display_child(view);
                         displayed = true;
                     }
                 }

IPython/html/static/notebook/js/widgets/container.js

@@ -25,8 +25,8 b' require(["../static/notebook/js/widget"], function(){'
             return IPython.WidgetView.prototype.update.call(this);
         },
 
-        display_child : function($element) {
-            this.$el.append($element);
+        display_child : function(view) {
+            this.$el.append(view.$el);
         },
     });