Using variable values form parametrized URL in Customer Exit in i_step = 1

Question

Hello BW experts,
I call a parametrized URL to a Web Template that has a Query with the variable VAR1:
http://XXX?...&CMD=LDOC&template_id=TEMP1&VAR_NAME_1=VAR1&VAR_VALUE_EXT_1=2006
Then I try to access the value of VAR1 in i_step = 1 in the Customer Exit for BEx variables in order to determine the value for a customer exit variable VAR2:
WHEN 'VAR2'.
    IF i_step = 1.
      READ TABLE i_t_var_range INTO var_range
        WITH KEY vnam = 'VAR1'.
      fl_var_range-sign = 'I'.
      fl_var_range-opt = 'EQ'.
      fl_var_range-low = *some operation with var_range
      APPEND fl_var_range TO e_t_range.
    ENDIF.
The problem is that VAR1 contains either the default values (if the variable is set to have default variables) or is empty (if there are no default variables defined). It does not retrieve the value in the URL in the Customer Exit, but displays it correctly in the variable screen.
Is there any way I can acces the URL parameter in the Customer Exit?
Thanks for any answers in advance.
Michael

Answer 1

Gili,
thanks for your answer. The problem was, though, that the first value determines the behavior of the variable screen by setting the value of a customer exit variable.
My goal was to have two variable screens. In the first a date is chosen and in the second a node of a time-dependant hierarchy is chosen. If one enters the date in the same screen as the hierarchy, the valid hierarchy for the date is not displayed.
I solved the problem now in following way:
<b>1. Saving the value in SAP Memory as a parameter.</b> The parameter has to be defined in SE80. A Dummy Web Template with a query on the same Infoprovider with just the two InfoObjects (Year/Month) displays a variable screen for Month/Year. In addition there is a Dummy Customer Exit variable that is needed in order to pass the variable values (month/year) into SAP Memory. Using JavaScript in the Dummy WebTemplate the second Web Template with the actual query is called without displaying anything else than the variable screen.
WHEN 'DUMMY_CUSTOMEREXIT_VAR'.
    data: w_date like sy-datum
    IF i_step = 2.
      READ TABLE i_t_var_range INTO var_range
        WITH KEY vnam = 'VAR1'.
    do your peration
    i.e.  w_date(4)+2 = var_range-low.
             w_date(6)+2 = var_range-high.
      SET PARAMETER ID 'ZBW_PARA1' FIELD w_date.
    ENDIF.
<b>2. Retrieving the value from SAP Memory</b> Before displaying the variable screen, the chosen date is retrieved from SAP Memory and used to set the date for a customer exit variable for the hierarchy validity date.
WHEN 'VAR2'.
    IF i_step = 1.
      GET PARAMETER ID 'ZBW_PARA1' FIELD w_date.
    do some operation with     
      APPEND fl_var_range TO e_t_range.
    ENDIF.
It is quite a comlex construct, but it works....