Formula Variable with customer Exit (ABAP Code)

Question

Hi Experts,
Please advise me wether i am going in the right way to achieve my requirment else please advise me any alternate approach and update me with the abap code for my customer exit as i am not familiar with ABAP.
My Requirment:
Data :
Emp_ID----Start_Date(DATS)---End_Date(DATS)
I had a user entry (intreval) VARIABLE created on Start_Date
User will enter the date intreval he want to analyze...
Ex: 01.01.2008 to 01.02.2008
Now i want to use the No of Days between user entered date intreval in my calculaction of a keyfigure
In the above example it is 31 days
So i created a Formula Variable of Customer Exit now i need a code that will
pass the user entered dates to
FM: FIMA_DAYS_AND_MONTHS_AND_YEARSImport parameters Value
I_DATE_FROM 01.01.2008
I_DATE_TO 01.02.2008
I_FLG_SEPARATE ' '
Export parameters Value
E_DAYS 31
E_MONTHS 1
E_YEARS 1
and need to pass the E_DAYS (31) to the result of formula
User Entry Variable (Intreval) : ZST_VAR
Formula Variable (Customer Exit) : ZND_EXIT
Code
WHEN 'ZND_EXIT'.
    DATA: low_date2 TYPE d,
    high_date2 TYPE d,
    num_days TYPE N,
    new_low_date2 TYPE d.
    IF i_step = 2.
      LOOP AT i_t_var_range INTO ls_varrange WHERE vnam = 'ZST_VAR'.
        CLEAR l_s_range.
        l_s_range-sign = 'I'.
        l_s_range-opt = 'EQ'.
        ls_varrange-low = low_date2.
        ls_varrange-high = high_date2.
CALL FUNCTION 'FIMA_DAYS_AND_MONTHS_AND_YEARS'
  EXPORTING
    I_DATE_FROM          = low_date2
    I_DATE_TO            = high_date2
    I_FLG_SEPARATE       = ' '
  IMPORTING
    E_DAYS               = NUM_DAYS
  l_s_range = NUM_DAYS.
  APPEND l_s_range TO e_t_range.
  EXIT.
  ENDLOOP.
  endif.

Answer 1

Hello,
Before the WHEN statement it shoud have a CASE statement. In the user exit coding place your WHEN statement anywhere between CASE...ENDCASE statement.
your code should look like
DATA: low_date2 TYPE d,
high_date2 TYPE d,
num_days TYPE N,
new_low_date2 TYPE d.
Case i_vnam.
WHEN 'ZND_EXIT'.
IF i_step = 2.
LOOP AT i_t_var_range INTO ls_varrange WHERE vnam = 'ZST_VAR'.
CLEAR l_s_range.
l_s_range-sign = 'I'.
l_s_range-opt = 'BT'.
low_date2 = ls_varrange-low.
high_date2 = ls_varrange-high.
CALL FUNCTION 'FIMA_DAYS_AND_MONTHS_AND_YEARS'
EXPORTING
I_DATE_FROM = low_date2
I_DATE_TO = high_date2
I_FLG_SEPARATE = ' '
IMPORTING
E_DAYS = NUM_DAYS
l_s_range-low = NUM_DAYS.
APPEND l_s_range TO e_t_range.
EXIT.
ENDLOOP.
endcase.
Thanks
Chandran