This event handler acts in a
similar fashion to a receive activity and allows a message to be received by a running
process from one of the process partner links.
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Within the BPEL process designer, an OnMessage event handler is displayed as
shown in the following figure:
BPEL designer also supports On Alarm events. An On Alarm event is triggered
at specified periods to perform certain processing. On Alarm events are useful for
timing out a process if no response is received from a client within a specified time
period. If an asynchronous process is pending information from a client, an On
Alarm event can be used to force the process to exit if no response is received within
the necessary time period.
To create an OnMessage or an On Alarm handler within the BPEL designer, we
need to add a Pick activity to the process designer.
Pick Activity
Pick activities are added to BPEL processes by dragging the Pick activity icon from
the palette onto the BPEL process. Right-clicking on a Pick activity gives you the
option of adding an OnMessage handler or an On Alarm message handler. Both of
these handlers allow additional actions to be performed after either the message is
received or the time out occurs simply by building up the BPEL process by dragging
additional actions from the palette.
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