s/target_name/model_name

IPython/html/static/widgets/js/manager.js

@@ -175,7 +175,7 @@ define([
         // Handle when a comm is opened.
         var that = this;
         var model_id = comm.comm_id;
-        var widget_type_name = msg.content.data.target_name;
+        var widget_type_name = msg.content.data.model_name;
         var widget_model = new WidgetManager._model_types[widget_type_name](this, model_id, comm);
         widget_model.on('comm:close', function () {
           delete that._models[model_id];

IPython/html/widgets/widget.py

@@ -140,7 +140,7 @@ class Widget(LoggingConfigurable):
     def open(self):
         """Open a comm to the frontend if one isn't already open."""
         if self.comm is None:
-            args = dict(target_name='ipython.widget', data={ 'target_name': self._model_name })
+            args = dict(target_name='ipython.widget', data={ 'model_name': self._model_name })
             if self._model_id is not None:
                 args['comm_id'] = self._model_id
             self.comm = Comm(**args)