notifyEventsAsync

notifyEventsAsync(recvr:  JadeGenericMessagingIF;
                  option: Integer);

The notifyEventsAsync method of the JadeGenericQueue class registers an object specified by the recvr parameter, which must implement the JadeGenericMessagingIF interface, for notifications through callback methods for the following events.

The parameters for the notifyEventsAsync method are listed in the following table.

Parameter Description
recvr Object that is to receive the callback notifications
option

The number of callback notifications, which can be specified using one of the following class constants.

  • Notify_OneShot (only the first event results in a callback notification, after which callbacks are canceled)

  • Notify_Continuous (every event results in a callback notification)

A process can register only one object to receive events for each queue. If the notifyEventsAsync method is called again, the new recvr object replaces the existing receiver of callback notifications.

To receive events for a queue, it must be opened by the openQueue method defined in the JadeMessagingFactory class, with Usage=Get or Usage=All included in the options parameter.

The following example shows the use of the notifyEventsAsync method to register an object for callbacks.

vars
    factory : JadeMessagingFactory;
    queue : JadeGenericQueue;
begin
    create factory transient;
    queue := factory.openQueue("JadeMQ://localnode/TestQ", "Usage=All");
    queue.notifyEventsAsync(receiver, JadeGenenericQueue.Notify_Continuous);
epilog
    delete factory;
end;