SAP IDoc Segment Data Reader: EDIDC, EDID4 and EDIDS in ABAP

REPORT ZEDI_IDOC_SEGMENT_READER.

TYPES: BEGIN OF ty_out,
         docnum   TYPE edidc-docnum,
         status   TYPE edidc-status,
         credat   TYPE edidc-credat,
         segnum   TYPE edid4-segnum,
         value    TYPE c LENGTH 70,
         lastmsg  TYPE c LENGTH 220,
       END OF ty_out.

DATA: lt_edidc  TYPE STANDARD TABLE OF edidc,
      ls_edidc  TYPE edidc,
      lt_edid4  TYPE STANDARD TABLE OF edid4,
      ls_edid4  TYPE edid4,
      lt_edids  TYPE STANDARD TABLE OF edids,
      ls_edids  TYPE edids,
      ls_seg    TYPE E1EDK01,
      lt_out    TYPE STANDARD TABLE OF ty_out,
      ls_out    TYPE ty_out,
      lr_status TYPE RANGE OF edidc-status,
      ls_status LIKE LINE OF lr_status,
      lv_text   TYPE string,
      lo_alv    TYPE REF TO cl_salv_table,
      lx_msg    TYPE REF TO cx_salv_msg.

PARAMETERS: p_mestyp TYPE edidc-mestyp DEFAULT 'ORDERS',
            p_idoctp TYPE edidc-idoctp DEFAULT 'ORDERS05',
            p_direct TYPE edidc-direct DEFAULT '2',
            p_status TYPE edidc-status DEFAULT '51',
            p_credat TYPE edidc-credat DEFAULT '20261001',
            p_max    TYPE i            DEFAULT 200.

START-OF-SELECTION.

  IF p_status IS NOT INITIAL.
    ls_status-sign   = 'I'.
    ls_status-option = 'EQ'.
    ls_status-low    = p_status.
    APPEND ls_status TO lr_status.
  ENDIF.

* 1. Control records
  SELECT docnum mestyp idoctp status credat
    FROM edidc
    INTO CORRESPONDING FIELDS OF TABLE lt_edidc
    UP TO p_max ROWS
    WHERE mestyp = p_mestyp
      AND idoctp = p_idoctp
      AND direct = p_direct
      AND status IN lr_status
      AND credat >= p_credat
    ORDER BY docnum DESCENDING.

  LOOP AT lt_edidc INTO ls_edidc.
    CLEAR ls_out.
    ls_out-docnum = ls_edidc-docnum.
    ls_out-status = ls_edidc-status.
    ls_out-credat = ls_edidc-credat.

*   2. Last status record and its message text
    CLEAR: lt_edids, ls_edids.
    SELECT * FROM edids
      INTO TABLE lt_edids
      UP TO 1 ROWS
      WHERE docnum = ls_edidc-docnum
      ORDER BY countr DESCENDING.
    READ TABLE lt_edids INTO ls_edids INDEX 1.
    IF sy-subrc = 0.
      IF ls_edids-stamid IS NOT INITIAL.
        MESSAGE ID ls_edids-stamid TYPE 'E' NUMBER ls_edids-stamno
                WITH ls_edids-stapa1 ls_edids-stapa2
                     ls_edids-stapa3 ls_edids-stapa4
                INTO ls_out-lastmsg.
      ELSE.
        ls_out-lastmsg = ls_edids-statxt.
      ENDIF.
    ENDIF.

*   3. Data records of the chosen segment
    SELECT docnum segnum segnam sdata
      FROM edid4
      INTO CORRESPONDING FIELDS OF TABLE lt_edid4
      WHERE docnum = ls_edidc-docnum
        AND segnam = 'E1EDK01'.
    IF sy-subrc <> 0.
      APPEND ls_out TO lt_out.
      CONTINUE.
    ENDIF.

    LOOP AT lt_edid4 INTO ls_edid4.
*     SDATA (1000 characters) cast onto the segment structure
      ls_seg = ls_edid4-sdata.
      ls_out-segnum = ls_edid4-segnum.
      ls_out-value  = ls_seg-BELNR.
      APPEND ls_out TO lt_out.
    ENDLOOP.
  ENDLOOP.

  TRY.
      cl_salv_table=>factory(
        IMPORTING r_salv_table = lo_alv
        CHANGING  t_table      = lt_out ).
      lo_alv->display( ).
    CATCH cx_salv_msg INTO lx_msg.
      lv_text = lx_msg->get_text( ).
      MESSAGE lv_text TYPE 'I'.
  ENDTRY.

* Reads control, data and status records of one IDoc in one call
*  DATA: ls_ctrl TYPE edidc,
*        lt_data TYPE STANDARD TABLE OF edidd,
*        lt_stat TYPE STANDARD TABLE OF edids.
*  CALL FUNCTION 'IDOC_READ_COMPLETELY'
*    EXPORTING
*      document_number         = ls_edidc-docnum
*    IMPORTING
*      idoc_control            = ls_ctrl
*    TABLES
*      int_edids               = lt_stat
*      int_edidd               = lt_data
*    EXCEPTIONS
*      document_not_exist      = 1
*      document_number_invalid = 2
*      OTHERS                  = 3.