ABAP Keyword Documentation → ABAP − Reference → SAP GUI User Dialogs → Selection Screens → Create Selection Screens → PARAMETERS
PARAMETERS - screen_options
Other versions: 7.31 | 7.40 | 7.54
Syntax
... { {[OBLIGATORY|NO-DISPLAY] [VISIBLE LENGTH vlen]}
| {AS CHECKBOX [USER-COMMAND fcode]}
| {RADIOBUTTON GROUP group [USER-COMMAND fcode]}
| {AS LISTBOX VISIBLE LENGTH vlen [USER-COMMAND fcode]
[OBLIGATORY]} }
[MODIF ID modid] ...
Extras
2. ... NO-DISPLAY
3. ... VISIBLE LENGTH vlen
4. ... AS CHECKBOX [USER-COMMAND fcode]
5. ... RADIOBUTTON GROUP group [USER-COMMAND fcode]
6. ... AS LISTBOX VISIBLE LENGTH vlen [USER-COMMAND fcode]
Effect
These additions can be used to declare the input field as a required field, hide the input field on the
selection screen, and define the visible length of the field. The input field can be displayed as a checkbox, radio button, or
dropdown list box.
The MODIF ID addition assigns all the screen elements of the parameter to the
modification group modid.
Note
Not all combinations of additions are valid. The syntax above shows the permitted combinations..
Addition 1
... OBLIGATORY
Effect
This addition defines the input field of the parameter on the selection screen as a required (obligatory) field. If no entry is made in this field, the user cannot use the Execute function (F8) to exit the selection screen; instead, the user can only use the functions Back, Exit, or Cancel.
Addition 2
... NO-DISPLAY
Effect
This addition specifies that no screen elements are generated for the parameter on the selection screen. In an
executable program,
a parameter of this type is used only as part of the interface defined by the selection screen. It can
be supplied with a value by the calling program when called with SUBMIT.
If the addition NO-DISPLAY is specified, a parameter can have any data types
except for reference types. These parameters can only be populated using the
WITH addition of the SUBMIT statement. In this case, unlike the general conversion rule for
deep types, the same rules apply as when importing data from a
data cluster.
Note
The length of a value passed to a parameter without input field is not subject to the 132 character restriction that applies to parameters that do have input fields.
Addition 3
... VISIBLE LENGTH vlen
Effect
This addition defines the visible length of the input field as vlen. Here,
vlen is entered directly as a positive number. If vlen
is less than the length of the parameter and less than the maximum visible length, the input field is
displayed in the length defined in vlen, with movable content. Otherwise, the addition is ignored.
Addition 4
... AS CHECKBOX [USER-COMMAND fcode]
Effect
This addition specifies that the input field in the first position of the selection screen is displayed as a
checkbox with the corresponding
description next to it on the right. The checkbox is selected if the value of para is "X" or "x". Otherwise, it is not selected.
This parameter must be created with type c and length 1. Explicitly specified
lengths len are not allowed. If the addition
TYPE is used, it can only be followed by the generic type c or a non-generic data type of type cand length 1.
The addition USER-COMMAND can be used to assign a function code fcode
to the parameter. The function code fcode must be specified directly and can only contain a maximum of 20 characters. To evaluate the function code, an
interface work area
of the structure SSCRFIELDS from ABAP Dictionary can be declared using
the statement TABLES. When the
user selects the checkbox on the selection screen, the runtime environment raises the event
AT SELECTION-SCREEN and passes the function code fcode
to the component ucomm of the interface work area sscrfields. If a function code used in the GUI status of the selection screen is specified for fcode, the
selection screen processing is affected accordingly.
Notes
-
If the
TYPEaddition is used to make a reference to a data type in ABAP Dictionary of type CHAR and length 1, and for which the valid values in the domain are defined as "X" and " ", the parameter is displayed automatically as a checkbox on the selection screen. -
The addition
USER-COMMANDcan, for example, be used for screen modifications with the additionMODIF ID(refer to example). -
If the addition
USER-COMMANDis specified without the addition AS CHECKBOX, and the parameter is of typecwith length 1, it is also displayed as a checkbox. Once again, explicit lengths cannot be specified. The additionOBLIGATORYis also possible in the syntax but does not make sense for a checkbox. -
It is not recommended that the system field
sy-ucomminstead ofsscrfields-ucommis evaluated, since this does not guarantee thatsy-ucommis always given the correct value in selection screen processing.
Addition 5
... RADIOBUTTON GROUP group [USER-COMMAND fcode]
Effect
This addition specifies that the input field is displayed as a
radio button in the first
position on the selection screen, and the output field is displayed next to it on the right. The radio
button is selected if the value of para is "X" or "x". Otherwise, it is not selected.
group is used to define the
radio button group
for the parameter. The name group is entered directly as a character string
with a maximum of 4 characters. Within a selection screen, there must be a minimum of two parameters
in the same radio button group. There cannot be more than one radio button group with the same name in one program, even if they are defined in different selection screens. If a radio button group is defined in a
block, all parameters of this group must be defined within the block.
This parameter must be created with type c and length 1. Explicitly specified
lengths len are not allowed. If the addition
TYPE is used, it can only be followed by the generic type c or a non-generic data type of type cand length 1.
In a radio button group, only one parameter can be defined with the addition
DEFAULT, and the specified value must be "X".
By default, the first parameter in a radio button group is set to the value "X" and the rest are set to " ".
The addition USER-COMMAND can be used to assign a function code fcode
to the first parameter in a radio button group. The function code fcode must be specified directly and can only contain a maximum of 20 characters. To evaluate the function code, an
interface work area
of the structure SSCRFIELDS from ABAP Dictionary can be declared using
the statement TABLES. When the
user selects any radio button from the radio button group on the selection screen, the runtime environment
raises the event AT SELECTION-SCREEN
and passes the function code fcode to the component ucomm
of the interface work area sscrfields. If a function code used in the GUI status of the selection screen is specified for fcode, the
selection screen processing is affected accordingly.
Notes
- We recommend that you arrange the radio buttons of a radio button group directly underneath each other. If the selection screen also contains other elements, we recommend that you define each radio button group within a block surrounded by a frame.
-
It is not recommended that the system field
sy-ucomminstead ofsscrfields-ucommis evaluated, since this does not guarantee thatsy-ucommis always given the correct value in selection screen processing.
Addition 6
... AS LISTBOX VISIBLE LENGTH vlen [USER-COMMAND fcode]
Effect
This addition creates a dropdown list box for an input field on the selection screen. The dropdown list box can be supplied with a selection list as follows:
- At the point in time AT SELECTION-SCREEN OUTPUT or AT SELECTION-SCREEN ON VALUE-REQUEST FOR para, the function module VRM_SET_VALUES can be called; the name of the parameter and a suitable list are passed in an internal table of type VRM_VALUES from type group VRM to this function module. The column TEXT of this table is displayed in the list box, and when a row is selected, the value from column KEY is added to the parameter.
- If the function module VRM_SET_VALUES is not called and the parameter is created with a data type from ABAP Dictionary, and the data type is associated with the input help in the dictionary, the first column of the input help is displayed in the list box.
-
Otherwise, a single-row list box is displayed containing the current value of the parameter.
The addition VISIBLE LENGTH must be used to specify the visible length of
the input field. The length must be specified explicitly since the length of the entries in the list box is usually different from the actual length of the parameter.
The addition USER-COMMAND can be used to assign a function code fcode
to the dropdown list box. The function code fcode must be specified directly and can only contain a maximum of 20 characters. To evaluate the function code, an
interface work area
of the structure SSCRFIELDS from ABAP Dictionary can be declared using
the statement TABLES. When the
user selects a row from the list box on the selection screen, the runtime environment raises the event
AT SELECTION-SCREEN
and passes the function code fcode to the component ucomm
of the interface work area sscrfields. If a function code used in the GUI status of the selection screen is specified for fcode, the
selection screen processing is affected accordingly.
Notes
-
Without the addition
USER-COMMAND, selecting a row in the dropdown list box does not raise the eventAT SELECTION-SCREEN. -
It is not recommended that the system field
sy-ucomminstead ofsscrfields-ucommis evaluated, since this does not guarantee thatsy-ucommis always given the correct value in selection screen processing.
Example
For parameter p, the system creates a dropdown list box, whose values are
created once for event AT SELECTION-SCREEN OUTPUT and then passed to function module VRM_SET_VALUES.
PARAMETERS p TYPE i AS LISTBOX VISIBLE LENGTH 10.
AT SELECTION-SCREEN OUTPUT.
CALL FUNCTION 'VRM_SET_VALUES'
EXPORTING
id = CONV vrm_id( 'P' )
values = VALUE vrm_values(
FOR i = 1 UNTIL i > 10
( key = i text = |Value { i }| ) ).
Example
For parameter p_carrid, the system creates a dropdown list box, whose values
originate from the input help for data type SPFLI-CARRID from ABAP Dictionary. The parameter p_carrid
is displayed with a length of 20 and filled with the label "Lufthansa". The user can select another
airline; in this case, the three-character airline ID is assigned to the parameter. When the function
code onli (associated with the function Execute
in the GUI status of the default selection screen) is assigned, the events AT SELECTION-SCREEN and START-OF-SELECTION are raised.
PARAMETERS p_carrid TYPE spfli-carrid
AS LISTBOX VISIBLE LENGTH 20
USER-COMMAND onli
DEFAULT 'LH'.
AT SELECTION-SCREEN.
...
START-OF-SELECTION.
...