Broker 10.5 | webMethods Broker Documentation | webMethods Broker Client C API Programmer's Guide | Subscribing to and Receiving Events | Event Subscriptions | Limits on Subscriptions
Limits on Subscriptions
The client group to which the BrokerClient belongs may limit the event types to which the Broker client may subscribe. See Client Groups for more information. The following example contains an excerpt from the subscribe1.c sample application that shows the use of the awCanSubscribe function to check for event subscription permission. The function requires these parameters:
*A BrokerClient handle.
*An event type name.
*A BrokerBoolean where subscription permission is returned.
. . .
BrokerClient c;
BrokerBoolean can_subscribe;
. . .
/* Check if can subscribe */
err = awCanSubscribe(c, "Sample::SimpleEvent", &can_subscribe);
if (err != AW_NO_ERROR) {
printf("Error on check for can subscribe\n%s\n", awErrorToString(err));
return 0;
if (can_subscribe == 0) {
printf("Cannot subscribe to event Sample::SimpleEvent.\n");
printf("Make sure it is loaded in the broker and \n");
printf("permission is given to subscribe to it in the \n");
printf("%s client group.\n", client_group);
return 0;
. . .
You can also use the awGetCanSubscribeNames function to obtain the names of all the event types to which a Broker client can subscribe.