Event blocks are used to handle events in the ABAP runtime environment. They are introduced by an event key word and finished by the next processing block. Since there is no closing statement, we recommend that you flag the end of an event block with 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
master program, and therefore
should not contain any of its own declarations. Exception: the event blocks AT SELECTION-SCREEN
GET ..., which 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 methods instead.
The following events exist:
- Program constructor event
This event occurs in all program types, except for class pools and interface pools.
- When the execution of each event block is completed, the statement
- With the exception of
AT SELECTION-SCREEN ...and GET ..., event blocks can be specified multiple times in a program. The event block
START-OF-SELECTIONcan also be specified more then once (implicitly). Whenever an event occurs, all associated event blocks are executed in the order of their occurrence. Where event blocks are specified implicitly multiple times, the extended program check produces a warning.