Exploring Classical Report Events in ABAP: Initialization and At Selection-Screen

 Welcome back everyone, So basically We were discussing about some best programming practices in our previous blog. Let’s discuss Classical Report Events.

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Events :-

• Classical Reports are the most basic ABAP reports, in which we display the output using WRITE statement.
• Event is always triggered by a specific action or a specific occurrence ( when a particular time has been reached ).
• The example of specific actions are mouse click, pressing a key etc. The example of specific occurrence is running out of memory etc.

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Classical Report Events :-

• The same concept of events is applicable to classical reports. Some events trigger by specific user action and some events trigger at specific occurrence in classical reports.

• The various classical report event are as follows :-

  • Initialization
  • At selection-screen
  • Start of Selection
  • End of Selection
  • Top of page
  • End of page
  • At selection screen output
  • At selection screen on value request for <field>
  • At selection screen on help request for <field>
  • At selection screen on <field>

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1. Initialization

• This event calls before displaying the selection screen / Input screen.
• The purpose of this event is to assign the default values to parameters and select options.

Let’s create a program, so that we can understand the events easily,

Code :-

***********************************************
*Start of Program
***********************************************
DATA : lv_pm   TYPE zar_payment_mode,
       lv_curr TYPE zar_curency,
       lv_date TYPE zar_order_date.

SELECT-OPTIONS : s_odate FOR lv_date NO-EXTENSION.
SELECT-OPTIONS : s_pm FOR lv_pm NO INTERVALS.
SELECT-OPTIONS : s_curr FOR lv_curr NO INTERVALS.

****************************
*Initializaton Events.
INITIALIZATION.
*****************
*For Date
s_odate-sign = 'I'.
s_odate-option = 'BT'.
s_odate-low = sy-datum - 100.
s_odate-high = sy-datum.
append s_odate.

********
*For Payement Mode
s_pm-low = 'C'.
append s_pm.

***************
*Currency
s_curr-low = 'INR'.
append s_curr.

*****************************************
*End OF Program
****************************************

Explanation :-

• In the above program, we have used our order header table which we have used in our previous blogs.
• We have created three select options for order date, payment mode, currency.
• Now, We will use initialization event to display the data on the input selection screen.
• Since, initialization event will be triggered just before displaying the input screen, So above code should display default entered value.
• Let’s run the program.

Output :-

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At Selection-Screen :-

• This event triggers when the user performs some action ( enter, click etc.) on the selection screen or input screen.
• The purpose of this event is to validate the input.
• At selection screen makes sure the output should be displayed according to the requirement of the user.

Now, suppose If I comment the payment mode from the initialization from the below code for payment mode.

Code :-

***********************************************
*Start of Program
***********************************************
DATA : lv_pm   TYPE zar_payment_mode,
       lv_curr TYPE zar_curency,
       lv_date TYPE zar_order_date.

SELECT-OPTIONS : s_odate FOR lv_date NO-EXTENSION.
SELECT-OPTIONS : s_pm FOR lv_pm NO INTERVALS.
SELECT-OPTIONS : s_curr FOR lv_curr NO INTERVALS.

****************************
*Initializaton Events.
INITIALIZATION.
*****************
*For Date
  s_odate-sign = 'I'.
  s_odate-option = 'BT'.
  s_odate-low = sy-datum - 100.
  s_odate-high = sy-datum.
  APPEND s_odate.

********
*For Payement Mode
*  s_pm-low = 'C'.
*  APPEND s_pm.

***************
*Currency
  s_curr-low = 'INR'.
  APPEND s_curr.

***********************************
*At Selection Screen
AT SELECTION-SCREEN.
if s_pm-low is INITIAL.
  if s_pm-low <> 'C'.
    MESSAGE 'Payment mode is not entered' type 'E'.
  endif.
ENDIF.
*****************************************
*End OF Program
****************************************

Selection Screen :-

Output Screen :-

• You can see the below message, It gets triggered after we press F8 on the selection screen.
• So, that’s why we say that At selection screen is used to validate the input.

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So, that’s enough for today.

Thanx a lot for being a part of this wonderful journey.