Centralized error handling class

Question

Hello Gurus!!!
I have developed coding for transaction fb03 in module pool program using OO concepts.
               Now I want to enhance my coding using centralized error handling class.
ie. the errors are not shown immediately but a class captures those errors and then they are sent to the calling class which displays those errors).
Kindly suggest your answers.
Thanks in advance,
Sachin

Answer 1

Dear Uwe,
I have implemented validation class which displays all the error messages through message class inside which I displayed error messages.
                The code is as follows :-
CLASS z_validation DEFINITION.
  PUBLIC SECTION.
    METHODS: check_company_code,
             check_docnr,
             check_fiscal_year.
ENDCLASS.                    "Z_Validation DEFINITION
      CLASS Z_Validation IMPLEMENTATION
CLASS z_validation IMPLEMENTATION.
  METHOD: check_company_code.
  if txt_codco = ' ' and txt_docno = ' ' and  txt_fisyr = ' '.
      MESSAGE i006.
  endif.
    IF txt_codco = ' '.
      MESSAGE i002.
      LEAVE TO SCREEN 0100.
    ELSE.
      SELECT t001~bukrs INTO CORRESPONDING FIELDS OF TABLE it_doc FROM t001
       WHERE t001~bukrs = txt_codco..
      IF sy-subrc NE 0.
        MESSAGE i000.
        LEAVE TO SCREEN 0100.
      ENDIF.
    ENDIF.
  ENDMETHOD.                    "Check_Company_Code
  METHOD: check_docnr.
    IF txt_docno = ' '.
      MESSAGE i003.
      LEAVE TO SCREEN 0100.
    ELSE.
      SELECT  belnr
       INTO CORRESPONDING FIELDS OF TABLE it_doc FROM bkpf
       WHERE bkpfbukrs = txt_codco AND bkpfbelnr = txt_docno.
      IF sy-subrc NE 0.
        MESSAGE i005.
        LEAVE TO SCREEN 0100.
      ENDIF.
    ENDIF.
  ENDMETHOD .                    "Check_Docnr
  METHOD: check_fiscal_year.
    IF txt_fisyr = ' '.
      MESSAGE i004.
      LEAVE TO SCREEN 0100.
    ELSE.
      SELECT gjahr
      INTO CORRESPONDING FIELDS OF TABLE it_doc FROM bkpf
      WHERE bkpfbukrs = txt_codco AND bkpfbelnr = txt_docno AND bkpf~gjahr = txt_fisyr.
      IF sy-subrc NE 0.
        MESSAGE i001.
        LEAVE TO SCREEN 0100.
      ENDIF.
    ENDIF.
  ENDMETHOD.                    "Check_Fiscal_Year
ENDCLASS.                    "Z_Validation IMPLEMENTATION
MODULE user_command_0100 INPUT.
  DATA: obj1 TYPE REF TO z_validation,
          obj2 TYPE REF TO z_data_processing,
          obj3 TYPE REF TO z_screen.
  CREATE OBJECT: obj1, obj2, obj3.
  CASE sy-ucomm.
    WHEN 'SEARCH'.
      CALL METHOD: obj1->check_company_code.
      CALL METHOD: obj1->check_docnr.
      CALL METHOD: obj1->check_fiscal_year.
      LEAVE TO SCREEN 0200.
  ENDCASE.
ENDMODULE.                 " USER_COMMAND_0100  INPUT
Please suggest your answer.
Thanks in advance,
Sachin