BAPI_ACC_DOCUMENT_POST Update reason code on BSEG

Question

Is the only way to update the reason code (BSEG-RSTGR) using the above bapi is by using the extension1 .
Tnks

Answer 1

I spent the last two days getting this working. It is really difficult but I got there in the end.
In the function module BAPI_ACC_DOCUMENT_POST in routine INIT_GLOBALS the program searches for an implementation of ACC_DOCUMENT. The filter is the document type which for this BAPI is BKPFF (two letter F's).
Later in routine CALL_BADI the methdo CHANGE is called of the implementation.
I copied the sample code from CL_EXM_IM_ACC+DOCUMENT into my Z BADI which I wittily called ZCL_IM_ACC_DOCUMENT. As I am changing the value of a field already in ACCIT I can leave the code exactly as is.
I then created my own structure (has to be all character fields regardless of the target field type in ACCIT), and filled up the extension table as follows just before calling the BAPI.
DATA: lt_extension2     TYPE STANDARD TABLE OF bapiparex
                                   WITH HEADER LINE,
          ls_extension2     TYPE zzbank_bapi_structure.
CLEAR ls_extension2.
        ls_extension2-posnr = 2.                  "Second Item
        ls_extension2-rebzg = gt_details-vbeln_vf."Invoice
        ls_extension2-rebzt = 'Z'.                "It's an invoice
        ls_extension2-rebzz = 1.                  "Item
        SELECT SINGLE gjahr FROM bkpf
          INTO ls_extension2-rebzj
          WHERE bukrs = gt_header-bukrs
          AND   belnr = gt_details-vbeln_vf.
The BAPI chooses ir's own posting keys, which we do not like
        IF gt_details-shkzg = 'S'."Normal
          ls_extension2-bschl = '15'."Incoming Customer Payment
        ELSE.
          ls_extension2-bschl = '05'."Outgoing Customer Payment
        ENDIF.
        lt_extension2-structure = 'ZZBANK_BAPI_STRUCTURE'.
        lt_extension2-valuepart1 = ls_extension2.
        APPEND lt_extension2.
The trick with BADIS is not just to activate the class but also the implemenation. I forget the second part every time.
Hope this helps.
Cheersy Cheers
Paul