How to call a function module dynamically?

Question

Hi
I am doing a smartform development and here my scenario.
<b>Scenario:</b>
There will be a simple report which will trigger a smartform output. The report has a selection screen and and in one of the field the user will enter the layout name or the layout name will be stored in the variant so that the user need not remember the layout name.
Based on the layout selected i need to show the output.
<b>What i have coded:</b>
In my program after selecting the data i am calling the FM SSF_FUNCTION_MODULE_NAME which will return the function module name to be called.
<b>Question:</b>
How do i call the function module dynamically. I cannot do a single call to the function module using the FM name derived from the above function call. I want to make the interface calling dynamic. We dont want to hardcode the function calls coz we may have many layouts to be called so how is it possible in SAP to call the FM interface dynamically.
~Suresh

Answer 1

Actually you can call the FM dynamically in by taking it into one variable and than use the CALL FUNCTION V_FM_NAME.
But the problem here is, you need to take care about the importing, exporting and tables parameters. They needs to be same for all FMs which you are planning to call. Otherwise system will give you a run time error.
   CALL FUNCTION 'SSF_FUNCTION_MODULE_NAME'
         EXPORTING  FORMNAME           = LF_FORMNAME
*                 variant            = ' '
*                 direct_call        = ' '
         IMPORTING  FM_NAME            = LF_FM_NAME
         EXCEPTIONS NO_FORM            = 1
                    NO_FUNCTION_MODULE = 2
                    OTHERS             = 3.
      CALL FUNCTION LF_FM_NAME
           EXPORTING
                      ARCHIVE_INDEX        = TOA_DARA
                      ARCHIVE_PARAMETERS   = ARC_PARAMS
                      CONTROL_PARAMETERS   = LS_CONTROL_PARAM
*                 mail_appl_obj        =
*                     mail_recipient       = ls_recipient
                      MAIL_SENDER          = LS_SENDER
Regards,
Naimesh Patel