Event Blocks

Event blocks are started using an event keyword and ended by the next processing block. As there is no closing statement, SAP recommends that you identify the end of an event block using a comment line.

Within an event block, no local data types or data objects can be declared. All declarative statements in event blocks belong to the ABAP program, and are visible in all subsequent processing blocks. An event block works with the global data types and data objects of the frame program, and therefore should not contain any of its own declarations. (Exception: The event blocks AT SELECTION-SCREEN ... and GET ... are implemented internally as procedures and can contain local data).

For reasons of data encapsulation, it is advisable to only implement a few functions in event blocks, and to call procedures instead.

The following events exist:

• Program constructor event
  This event occurs in all program types.

• Reporting events
  These events only occur in executable programs.

Selection screen events and list events occur during selection screen processing or list processing, and are described in these processes.

Note

• When the execution of each event block is completed, instruction NEW-LINE is executed.

• With the exception of AT SELECTION-SCREEN ... and GET ... können event blocks can be listed multiple times in a program. Event block START-OF-SELECTION can also be implicitly listed multiple times. Whenever an event occurs, all associated event blocks are executed in the order of their occurrence. Where event blocks are implicitly listed multiple times, the extended program check posts a warning.