Chapter 2: A Fusion Applications Technical Overview 45 3. The user completes the form and clicks the submit button. The request invokes any embedded ADF validations (Groovy, and so on) and fires the controller code. The controller methods commit some data (via entity objects) at this point. 4. The controller and the page then raise an associated business event within the ADFbc layer and any associated subscriptions are triggered (via EDN). Where the next step represents a large piece of work, the processing may split so that the user session is released to continue forward and the back-end processing runs behind the scenes. 5. Event subscriptions invoke the Mediator to handle subsequent messaging to and from an associated BPEL process flow. 6. The BPEL Process Manager starts the flow and executes the associated steps based on the data it has received. As it runs, it retains context data and runs associated web service calls in and out of the BPEL process, also orchestrated by the BPEL Process Manager and the