I was recently working on a simple process in PCS for a license approval flow. Given the purists that I am, I began by defining definitions for the various message based activities used in the process flow. The process was an asynchronous process with a few intermediate events. A simplified snippet is shown here for visualization.
In order to implement the above process, I created a service definition (WSDL) with the following schematic. As you can notice, there is a portType for accepting requests into the process (fc.myst.bp.TestDrive) and a callback portType for sending messages out of the process (fc.myst.bp.TestDrive.CallBack). Each of the portTypes have operations for catch and throw messages respectively. Read the complete article here.
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