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Difference between initilization and default

Former Member
0 Kudos

Difference between initilization and default.

when we will use initilization and default while making the input selection field values default.

what are the selection screen events.

7 REPLIES 7

Former Member
0 Kudos

Hi,

You can use any one of default or intialization while dealing with variables , but in case of structures and tables you have to use intialization to assign it intial value.

& the selection-screen events are

Syntax

...

| { ON {para|selcrit} }

| { ON END OF selcrit }

| { ON BLOCK block }

| { ON RADIOBUTTON GROUP radi }

| { }

| { ON {HELP-REQUEST|VALUE-REQUEST}

| FOR {para|selcrit-low|selcrit-high} }

| { ON EXIT-COMMAND }.

Alternatives:

1. ... OUTPUT

2. ... ON {para|selcrit}

3. ... ON END OF selcrit

4. ... ON BLOCK block

5. ... ON RADIOBUTTON GROUP radi

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 at the screen event PBO of a selection screen. In the event block, the selection screen can be prepared through assignments to the data objects of parameters and selection criteria and through 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 inputs from previous displays of the same selection screen. Assignments in the event blocks LOAD-OF-PROGRAM oder INITIALIZATION, on the other hand, only have an effect at first program start.

Alternative 2

... ON {para|selcrit}

Effect

This event is triggered at 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. In the event block, the user input can be checked. 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. In the event block, the entire selection table can be checked.

Alternative 4

... ON BLOCK block

Effect

This event is triggered at 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. In the event block, the user inputs can be checked. 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 radi

Effect

This event is triggered at the screen event PAI of a selection screen if all the fields of a radio button group radi of the selection screen were passed to the ABAP program. In the event block, the user input can be checked. Sending a warning or error message in the event block makes all the radion buttons of the block radi 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. In this event block, all the user inputs can be checked. 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 at 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 possibly defined in the 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 a possibly linked logical database.

With the events for the field and input help, no data is transported between the selection screen and the ABAP program. As with general screens, suitable function modules must be used for these. 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. In the event block, possible clean-up actions can be executed.

Example

In these executable programs, a standard selection screen and a further selection screen are defined. In the event blocks AT SELECTION-SCREEN, the inputs in the selection screens can be specially handled using the name p_carrid and the screen number in sy-dynnr.

REPORT demo_at_selection_screen.

  • Global data

DATA: sflight_tab TYPE TABLE OF sflight,

sflight_wa LIKE LINE OF sflight_tab.

  • Selection screens

PARAMETERS p_carrid TYPE spfli-carrid.

SELECTION-SCREEN BEGIN OF SCREEN 500.

SELECT-OPTIONS s_conn FOR sflight_wa-connid.

DATA s_conn_wa LIKE LINE OF s_conn.

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 sflight

INTO TABLE sflight_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.

...

reward if helpful

Former Member
0 Kudos

Hi,

in selection screen if u want the some defalut value to be passed with out any calculations or something else like that then we will use default.

for exampl in the slection screen u have a filed to ener date there by default u want to display some default date as todays date then

parameters:

p_date like sy-datum default sy-datum.

but initialization is a event which triggers even before the selection screen comes so if u want some calculations to be performed then u will write there and get the value and u will display it in selection scren.

ex:

if u want to displays two days back date as default

then

parameters:

p_date like sy-datum.

initilization.

p_date = sy-datum - 2.

Regards,

Shiva KUmar

Former Member
0 Kudos

In Selection screen itself you can specify default values like

parameters : p_num(3) value '100'.

INITIALIZATION

Point before the selection screen

is displayed

When you start a program in which a selection screen is defined (either in the program itself or in the linked logical database program), the system normally processes this selection screen first. If you want to execute a processing block before the selection screen is processed, you can assign it to the event keyword INITIALIZATION.

Reward if useful.

Anita

Former Member
0 Kudos

Subba,

Wen u initialize a particular field of a selection-screen, u r populating some data to the selection-screen table of the same field. But wen u set a default value for any field of a screen then u r just giving it a default value which can be changed by the user at the time of program execution.

U do he initialization in the event INITIALIZATION but for setting a default value u do the same while declaring a field or a variable.

Regards,

Jayadeep

Former Member
0 Kudos

hi,

1) default is used where u are setting the value when the prog. is exectuted each time.

2) now value is set

3) now in ur prog. this value might be changed according to ur logic or requirement.

4) after few changes to the value , now u require to set the value again to the initial position ( value at the time the prog is executed)

5) then u wil use initial. to set the default valu again.

reward if helpful

regards

mano

Former Member
0 Kudos

hi,

1) default is used where u are setting the value when the prog. is exectuted each time.

2) now value is set

3) now in ur prog. this value might be changed according to ur logic or requirement.

4) after few changes to the value , now u require to set the value again to the initial position ( value at the time the prog is executed)

5) then u wil use initial. to set the default valu again.

reward if helpful

regards

mano