ABAP Keyword Documentation → ABAP - Reference → User Dialogs → Selection Screens → Selection Screen Processing → AT SELECTION-SCREEN
AT SELECTION-SCREEN - selscreen_event
Other versions: 7.31 | 7.40 | 7.54
Syntax
... { OUTPUT }
| { ON {para|selcrit} }
| { ON END OF selcrit }
| { ON BLOCK block }
| { ON RADIOBUTTON GROUP group }
| { }
| { ON {HELP-REQUEST|VALUE-REQUEST}
FOR {para|selcrit-low|selcrit-high} }
| { ON EXIT-COMMAND }.
Alternatives
2. ... ON {para|selcrit}
3. ... ON END OF selcrit
4. ... ON BLOCK block
5. ... ON RADIOBUTTON GROUP group
6. ... {
}
7. ... ON {HELP-REQUEST|VALUE-REQUEST} FOR {para|selcrit-low|selcrit-high}
8. ... ON EXIT-COMMAND
Effect
These additions allow individual evaluation of specific elements of the
selection screens
of the program. The information as to which selection has triggered the event is contained in the system field sy-dynnr.
Alternative 1
... OUTPUT
Effect
This event is triggered by the screen event PBO of a selection screen. In the event block, the selection screen can be prepared using assignments to the data objects of parameters and selection criteria and using dynamic screen modifications.
Note
The assignments to input fields in the event block AT SELECTION-SCREEN OUTPUT
always affect the selection screen and overwrite the user input from previous displays of the same selection
screen. Assignments in the event blocks LOAD-OF-PROGRAM
or INITIALIZATION, on the other hand, only have an effect the first time the program starts.
Alternative 2
... ON {para|selcrit}
Effect
This event is triggered by the screen event
PAI of a selection screen if the content of the input field of a parameter para or a line of a
selection
criterion selcrit was passed to the ABAP program. The user input can be checked in this event block. Sending a
warning or an
error message in the
event block makes the fields para and selcrit ready for input again.
No parameter that is defined as a radio button can be specified. For this purpose, the addition ON RADIOBUTTON GROUP is provided.
Note
If a user action takes place in the dialog box for the multiple selection of a selection criterion selcrit, the entries of the
selection table are
passed to the program, line by line. For each line, the event AT SELECTION-SCREEN ON selcrit is triggered.
Alternative 3
... ON END OF selcrit
Effect
This event is triggered after the selection table selcrit has been fully
passed to the program after a user action in the dialog box for the multiple selection has taken place. The entire selection table can be checked in this event block.
Alternative 4
... ON BLOCK block
Effect
This event is triggered by the screen event PAI of a selection screen if all the input fields of a block
block of the selection screen were passed to the ABAP program. The user input
can be checked in the event block. Sending a warning or an error message in the event block makes all the fields of the block block ready for input again.
Alternative 5
... ON RADIOBUTTON GROUP group
Effect
This event is triggered by the screen event
PAI of a selection screen if all the fields of a radio button group group of the selection screen were passed to the ABAP program. The user input can be checked in this event block. Sending a
warning or
error message in the event block makes all the radio buttons of the group group ready for input again.
Note
The individual fields of a radio button group are not passed individually and do not trigger the event AT SELECTION-SCREEN ON par.
Alternative 6
... { }
Effect
The event AT SELECTION-SCREEN itself is triggered as the last event of selection
screen processing if all the input values were passed to the program. All user input can be checked
in this event block. Sending a warning or an error message in the event block makes all the screen fields ready for input once again.
Alternative 7
... ON { HELP-REQUEST | VALUE-REQUEST } FOR {para|selcrit-low|selcrit-high}
Effect
The two events ON HELP-REQUEST and ON VALUE-REQUEST are triggered by the screen events
POH and
POV of a selection screen if, for the input field of a parameter para or one of the input fields of a
selection criterion
selcrit, the field help F1 or the input help F4 was called. Other
selection events are not triggered.
In the event blocks, a self-defined field or input field can be programmed, which overrides any helps defined in ABAP Dictionary.
Notes
- These event blocks can only be implemented for fields of the selection screen that are defined in the same ABAP program and not in any associated logical database.
-
The events for the field help and input help do not transport data between the selection screen and the ABAP program. As with general
screens, suitable function modules
such as RS_SELECTIONSCREEN_READ and RS_SELECTIONSCREEN_UPDATE must be used for this. The parameters and selection criteria changed for the input help are transported to the selection screen.
Alternative 8
... ON EXIT-COMMAND
Effect
This event is triggered if the user has called one of the functions Back, Exit, or Cancel. Any cleanup actions can be executed in this event block.
Example
This executable program
defines a standard selection screen and a further selection screen. In the event blocks AT
SELECTION-SCREEN, the input in the selection screens can be specially handled using the evaluation of the name p_carrid and the
screen number in sy-dynnr.
REPORT demo_at_selection_screen.
* Global data
DATA: spfli_tab TYPE TABLE OF spfli,
spfli_wa LIKE LINE OF spfli_tab.
* Selection screens
PARAMETERS p_carrid TYPE spfli-carrid.
SELECTION-SCREEN BEGIN OF SCREEN 500.
SELECT-OPTIONS s_conn FOR spfli_wa-connid.
SELECTION-SCREEN END OF SCREEN 500.
* Handling selection screen events
AT SELECTION-SCREEN ON p_carrid.
IF p_carrid IS INITIAL.
MESSAGE 'Please enter a value' TYPE 'E'.
ENDIF.
AUTHORITY-CHECK OBJECT 'S_CARRID'
ID 'CARRID' FIELD p_carrid
ID 'ACTVT' FIELD '03'.
IF sy-subrc = 4.
MESSAGE 'No authorization for carrier' TYPE 'E'.
ELSEIF sy-subrc <> 0.
MESSAGE 'Error in authority check' TYPE 'A'.
ELSE.
IF sy-ucomm = 'ONLI'.
CALL SELECTION-SCREEN '0500'.
ENDIF.
ENDIF.
AT SELECTION-SCREEN.
IF sy-dynnr = '0500'.
IF s_conn IS INITIAL.
MESSAGE 'Please enter values' TYPE 'W'.
ELSE.
SELECT *
FROM spfli
INTO TABLE spfli_tab
WHERE carrid = p_carrid AND
connid IN s_conn.
IF sy-subrc <> 0.
MESSAGE 'No flights found' TYPE 'E'.
ENDIF.
ENDIF.
ENDIF.
* Main program
START-OF-SELECTION.
...