937                 errors[attr] = session._("can't change the %s attribute") % \

   937                 errors[attr] = session._("can't change the %s attribute") % \

   938                                display_name(session, attr)

   938                                display_name(session, attr)

   939     if errors:

   939     if errors:

   940         raise ValidationError(entity.eid, errors)

   940         raise ValidationError(entity.eid, errors)

   941 

   941 

   943 

   942 

   944 class AfterDelRelationTypeHook(SyncSchemaHook):

   943 class AfterDelRelationTypeHook(SyncSchemaHook):

   945     """before deleting a CWAttribute or CWRelation entity:

   944     """before deleting a CWAttribute or CWRelation entity:

   946     * if this is a final or inlined relation definition, instantiate an

   945     * if this is a final or inlined relation definition, instantiate an

   947       operation to drop necessary column, else if this is the last instance

   946       operation to drop necessary column, else if this is the last instance