Fundamentals of events in ABAP Objects

Events are like one of the class components, events are triggered when certain set of
conditions is met, and unlike normal method they cannot be called using the call method statement. Events denote the state of an object, that is what is the current status of an object, in layman’s word events adds the dimension of time to the modeled entity.

Events enable objects or classes to trigger event handler methods in other objects or classes. Whereas a method can have any number of callers in regular method calls, any number of event handler methods can be called by triggering an event The life of an event consists of four stages.

1. Creating an event
   Creating an event handler method for the event
   Registering the handler method to the event
   Raising the event

Few points to note:

Events have a parameter interface similar to methods; however, they have only output
parameters, no input parameters. These parameters can be passed to the event handler methods by the triggering object/class (statement RAISE EVENT). The event handler methods use them as input parameters.

Code:



Creating an event
Events can be created like normal class component
CLASS test DEFINITION.
PUBLIC SECTION.
EVENTS: test_event.
ENDCLASS.