The fnName property is available only for the following JSDO event or in the request object returned to a jQuery Promise callback:
afterInvoke
This request object property is also available for any session online and offline events that are fired in response to the associated resource operation when it encounters a change in the online status of the JSDO login session (JSDOSession or Session object). The request object is itself passed as a parameter to any event handler functions that you subscribe or register to JSDO events, the jQuery Promise returned from an invoke( ) method, and to the online and offline events of the session that manages Data Object Services for the JSDO. This object is also returned as the value of any JSDO invocation method that you execute synchronously.
Note: The value of the fnName property is the same as that of the op-name parameter passed to the subscribe( ) method that subscribed to the current invoke operation event.