ABAP is an event driven Programming language. ABAP Report Events are used to handle different kinds of events during runtime. It starts with the event name, followed by the programming codes belonging to that event. Classical reports in SAP ABAP are the reports which contain both selection screens and output screens.
It is advisable to use Comment line to declare the end of an event, since Events do not have a closing Keyword and it ends as soon any other Event starts.
There are different kinds of events in ABAP; SAP has categorized these events together.
Categories of Classical Report Events in SAP ABAP:
There are four categories of Events in ABAP:
Events in the Category
Except Pool programs it occurs in every programs.
These events occur only in Executable Reports.
These events occur during Selection Screen Processing
AT SELECTION-SCREEN OUTPUT
These events occur during Classical List Processing [List can be a table or consecutive Write statements, etc.]
Events of Classical Reports in SAP ABAP:
Classical Reports have following events:
- LOAD-OF-PROGRAM : First event fired, loads program in memory
- INITIALIZATION: Initialize variable
- START-OF-SELECTION : Actual Business Logic (After START-OF-SELECTION)
- END-OF-SELECTION : To end above
- AT SELECTION-SCREEN : To validate Multiple Input fields (After Initialization and before START-OF-SELECTION) (After
- AT SELECTION-SCREEN OUTPUT: To manipulate Dynamic screen
- AT SELECTION-SCREEN ON
- AT SELECTION-SCREEN ON END OF
- AT SELECTION-SCREEN ON BLOCK
- AT SELECTION-SCREEN ON RADIOBUTTON GROUP
- AT SELECTION-SCREEN ON VALUE REQUEST
- TOP-OF-PAGE : To print heading
- END-OF-PAGE: To print footer
- Never use Selection Screen Events in Function Module
- Use LOAD-OF-SCREEN to load default values for the type of Reports executed via SUBMIT or using a transaction code
- Use INITIALIZATION to load default values for the executable type of Reports
- It is advised not to specify an event more than once [Except AT-SELECTION-SCREEN & GET event, all other can be specified multiple times.]
- If you are not specifying any event name, still specify START-OF-SELECTION to improve readability
- After every execution of events NEW-LINE event is executed automatically.