Using Contextual Events: Step 2
Create the method that constructs the payload and expose it as a data control: After you have designated the producer and the consumer, you can determine what data, or payload, the consumer of the event requires to refresh its region appropriately. This can be as simple as passing a foreign key value, but some complex business logic may be required to produce the data needed by the consumer region. In any case, you need to create a method to construct the event payload. This can be in a separate Java class, or it can be a service method in the application module. The method must always return the event payload.
No matter how you create the method, you must expose it as a data control. If it is in a separate Java class, you can simply drag it to the Data Control Palette. If it is an application module method, you must expose it to the client interface.