fix #189: hide Group ID for unregistered users

angular_app/event-edit.html

@@ -78,7 +78,7 @@
                         <span class="input-group-addon min100">{{'Where' | translate}}</span>
                         <input type="text" class="form-control" placeholder="{{'Where' | translate}}" ng-model="event.where">
                     </div>
-                    <div class="input-group input-group top5">
+                    <div ng-if="!eventFormDisabled" class="input-group input-group top5">
                         <span class="input-group-addon min100">{{'Group ID' | translate}}</span>
                         <input type="text" class="form-control" placeholder="{{'Used to share persons amongst multiple events. Must be hard to guess (if empty, will be autogenerated)' | translate}}" ng-model="event.group_id">
                     </div>

eventman_server.py

@@ -632,6 +632,8 @@ class EventsHandler(CollectionHandler):
                 self._check_number_of_tickets(event)
             except InputException:
                 event['no_tickets_for_sale'] = True
+            if not self.has_permission('event|write'):
+                event['group_id'] = ''
             if not self.has_permission('tickets-all|read'):
                 event['tickets'] = []
         return event