Hi Ravi,
The event type refers to the workflow event that is being called. For instance, an event type can be when your approvable gets Approved. You’d really only be defining these for eForms, as you should not be creating events for Ariba defined approvables. The event type can also be referred to in the CreateDurableEvent Action. So for instance, once your approvable enters the Approved state, you may want to define an action perform further processing of the approvable. In this case, you’d also fire the CreateDurableEvent Action and it takes the parameter “EventType” where you’d refer to the Approvable:Approved.
The eventSource is something that would very unlikely that you’d ever have to define in a workflow extension or in an eform workflow. But it’s a type of Action. In fact eventSource is a subclass of Action. It’s used as an event action to listen to another type of object related to the object that is being workflowed. For example when workflowing an Invoice or charge, an event may want to operate on the related Reconciliation object.
The contextObject is the object on which a given action will take effect on. So in workflow, it’s the approvable object that is the default contextObject (ex: a Requisition or Receipt, etc.). You don’t need to specify this in the code as it’s the default. If however you want the context to be the object that triggered the event, you need to specify the contextObject as EVENT_SOURCE. It’s very rare that you’d ever have to define contextObject, but it’s good to know what it is. In your Action java code, the correlation to the contextObject is the ValueSource which is passed into the fire method. Typically you’d check the ValueSource is an instanceof the object type you’re expecting, then operate.
Hope that helps,
Scott