Once the workflow extensions are enabled using default workflow executors, they create respective approval tasks in WSO2 Business Process Server. Each of these tasks are visible for Administrators in Admin Dashboard. Administrator has the option to accept or reject each of the requests made by other users. But users have the option to delete the application, subscription, key they created before administrator choose to accept or reject the requests. This leaves unnecessary approval requests in Admin Dashboard which can confuse the administrator.
API Manager provides task clean up feature to prevent deleted items showing up in Admin Dashboard. WorkflowExecutor class has been introduced with cleanUpPendingTask(String workflowExtRef) method which is triggered by application or subscription deletion. This method implements the logic to notify the WSO2 Business Process Server that a task with id workflowExtRef is deleted. BPEL process in Business Process Server should also have an understanding of how to exit a created process. Therefore BPEL process should contain an cancel event to support process cancellation. Each BPEL should have the support for cancel event implemented in order to successfully cleanup unnecessary tasks. Check BPEL Correlation Guide and Process Correlation for more information on BPEL Correlation.