Catching event throws

Processes catch events to react to event throws that occur during the execution of an operation. You can configure filters for catches of asynchronous and timer events that determine whether the event is acted on. Event filters are based on the information in the event data. Furthermore, the event data and the event message data can be saved as process data. When you catch exception events, you specify the type of exception that is acted on.

Event catches are attached to operations on the process diagram and appear as icons in one of the corners of the operation icon. Operations can catch a maximum of four event types.

The event catch reacts to thrown events only while the operation that it is attached to is executing:

  • If the event is caught during the execution of the operation, the route (if any) that begins at the event catch is followed, and the operation stops executing.

  • If the operation completes and the event type that is being caught is not thrown, the usual evaluation of routes that originate at the operation occurs.

A.
Event catch

B.
Route followed if event is caught

C.
Route followed if operation is complete and no event is caught

Many service operations include an exception event catch by default, which is used to handle exceptions that occur when the operation executes. The developer of the service defines the exception events that are thrown. For information about the exceptions that each operation throws, see Service reference.