You can define events as class members that allow you to send (publish) notification of any run-time conditions that you detect. Your application can then respond to this notification by executing one or more methods and internal procedures (event handlers) that you specify (subscribe) for the event. ABL allows you to define a class event with a name and a signature using the DEFINE EVENT statement. The signature defines the parameters (if any) that any subscribed event handler must have.
For more information on Object-oriented programming, see the guide OpenEdge Development: Object-oriented Programming.