Field symbols in EXIT_SAPLEINS_001, GETWA_NOT_ASSIGNED

Question

I am working with purchase order BI content in LO Cockpit.  I enhanced the communications structure to add extra fields and use the EXIT_SAPLEINS_001 to provide before and after images upon firing of the 'MA' event.
I use field symbols to access internal tables in
shared memory for delta extractor after-images (like in following code snippet):
new_val = '(SAPLEINS)T_EKBE[]'.
ASSIGN (new_val) TO <fs>.
IF sy-subrc = 0.
  it_ekbe[] = <fs>.
ENDIF.
UNASSIGN <fs>.
The problem is that (SAPLEINS)T_EKBE[] is not always defined in memory.  For example, it is defined during the initial data extraction, but not when creating a new PO.  As a result, the user exit crashes at the ASSIGN statement with exception GETWA_NOT_ASSIGNED when creating a new PO.
I tried using a try...catch block, but was unable to catch the exception.  I don't know of any way to tell if a variable is defined other than attempting an ASSIGN statement of the form ASSIGN ('(ProgramName)variable') TO field-symbol which crashes if the the variable is not defined.  Any ideas?

Answer 1

Hello,
enhance your IF-Statement like this:
new_val = '(SAPLEINS)T_EKBE[]'.
ASSIGN (new_val) TO <fs>.
IF sy-subrc = 0 AND <fs> IS ASSIGNED.
  it_ekbe[] = <fs>.
ENDIF.
UNASSIGN <fs>.
Regards,
André Klos