Web API and external implementations
IBM® BPM includes a sample external implementation that illustrates how to use IBM BPM web API operations when developing a custom application to enable process participants to complete a particular step within a process instance.
You can use external implementations to create your own implementation of a service that is invoked as part of the process. When you do this, you have access to the process context and this access is provided by the web API.
When a process instance reaches a step handled by an external implementation, the process server does not invoke the custom application. Instead, after passing all necessary process data to the custom application, the process server ceases its work on the process instance. When the custom application completes, the process server resumes its work on the process instance, using any updated process data received from the custom application.
Sample
The Samples Exchange on Blueworks Live includes a sample external implementation. It is a custom Eclipse application that enables managers to either approve or reject expense reports from their employees. It represents one step in a process and can be modeled as an external implementation in Process Designer. If you import the BPD External Implementation Library and other associated components in the ExpenseApproval.twx file from the sample, the Eclipse application, combined with the corresponding library items, is a complete working example of external implementations.