Use url_name as component_id in published events

mentoring/mentoring.py

@@ -152,18 +152,11 @@ class MentoringBlock(XBlockWithLightChildren):
             return {'result': 'error', 'message': 'Missing event_type in JSON data'}
 
         data['user_id'] = self.scope_ids.user_id
-        data['component_id'] = self._get_unique_id()
+        data['component_id'] = self.url_name
 
         self.runtime.publish(self, event_type, data)
         return {'result':'success'}
 
-    def _get_unique_id(self):
-        try:
-            unique_id = self.location.name
-        except AttributeError:
-            # workaround for xblock workbench
-            unique_id = self.parent.replace('.',  '-')
-        return unique_id
 
     @property
     def title(self):