Retrieving missing data from user exit functions

DATA: i_EDIDC like EDIDC,
      i_EDIDD like EDIDD occurs 0 with header line.

CONSTANTS:
      c_EDIDD(21)  value '(SAPLV55K)IDOC_DATA[]',
      c_EDIDC(21)  value '(SAPLV55K)IDOC_CONTRL',
      c_E1ADRM1(7)      value 'E1ADRM1'
      c_SHPCON(6)  value 'SHPCON'.

Field-symbols: <FC>, <FD> .
clear: i_EDIDC, i_EDIDD.
refresh: i_EDIDD.

* Get the Control Record from memory
assign (c_EDIDC) to <FC>.
if SY-SUBRC = 0.
  i_EDIDC = <FC>.

  IF i_EDIDC-MESTYP = c_SHPCON.

*   None of the partner information can be passed directly from
*   the IDOC function, so we'll get it from memory.

*   Get IDOC data records from memory
    assign (c_EDIDD) to <FD>.
    i_EDIDD[] = <FD>.

*   Now you have the entire IDOC available to you without making
*   a DB select.
    read table i_EDIDD with key SEGNAM   = c_E1ADRM1.

*   Load new value HERE...

  ENDIF.
ENDIF.