abap-code-patterns

name	abap-code-patterns
description	ABAP development patterns and best practices — BAPI/RFC, dynamic programming, Clean ABAP, DDIC design, exception handling, BAL logging, ABAP OO. Use when writing, reviewing, or refactoring ABAP code; implementing ZROUTER handlers.
trigger	["ABAP pattern","ABAP best practice","Clean ABAP","BAPI pattern","dynamic ABAP","ABAP OO design","ZROUTER handler","refactor ABAP","ABAP exception handling","BAL logging"]

ABAP Code Patterns

Reference for ABAP development in ZROUTER_DISPATCH and related SAP projects. Validated against Clean ABAP guidelines and abaplint rules.

Prerequisites

• SAP NetWeaver 7.40+ (inline declarations, VALUE, COND, FOR)
• abaplint configured (config in package.json abaplint key, or root abaplint.json)
• Access to SE80/ADT for object creation

1. BAPI/RFC Pattern

" BAPI call with proper commit/rollback
CALL FUNCTION 'BAPI_MATERIAL_SAVEDATA'
  EXPORTING headdata = ls_header
  IMPORTING return   = ls_ret.

IF ls_ret-type = 'E' OR ls_ret-type = 'A'.
  CALL FUNCTION 'BAPI_TRANSACTION_ROLLBACK'.
  RAISE EXCEPTION TYPE cx_zrouter EXPORTING mv_text = ls_ret-message.
ELSE.
  CALL FUNCTION 'BAPI_TRANSACTION_COMMIT' EXPORTING wait = 'X'.
ENDIF.

2. GENERATE SUBROUTINE POOL (Dynamic Eval)

" Compile ABAP at runtime — lighter than INSERT REPORT + SUBMIT
DATA: lt_source TYPE TABLE OF string,
      lv_pool   TYPE string.

APPEND |PROGRAM.| TO lt_source.
APPEND |FORM eval CHANGING cv_result TYPE string.| TO lt_source.
APPEND LINES OF lt_lines TO lt_source.
APPEND |ENDFORM.| TO lt_source.

GENERATE SUBROUTINE POOL lt_source NAME lv_pool
  MESSAGE DATA(lv_msg) LINE DATA(lv_line) WORD DATA(lv_word).

IF sy-subrc <> 0.
  RAISE EXCEPTION TYPE cx_zrouter
    EXPORTING mv_text = |Syntax error line { lv_line - 2 }: { lv_msg }|.
ENDIF.

PERFORM ('EVAL') IN PROGRAM (lv_pool) IF FOUND CHANGING cv_result.

3. Clean ABAP Quick Rules

1. Field lists: SELECT matnr, maktx FROM mara — never SELECT *
2. Inline declarations: DATA(lv_matnr) = 'MAT001'
3. NEW operator: mo_log = NEW zcl_logger( ) — not CREATE OBJECT
4. VALUE: lt_data = VALUE #( ( a = 1 ) ( a = 2 ) )
5. COND/SWITCH: lv_st = COND #( WHEN sy-subrc = 0 THEN 'OK' ELSE 'ERR' )
6. Field symbols: LOOP AT lt_tab ASSIGNING FIELD-SYMBOL(<ls>)
7. No COMMIT WORK: Use BAPI_TRANSACTION_COMMIT with wait = 'X'
8. Exceptions: Inherit CX_STATIC_CHECK, never CX_ROOT
9. JSON: Use /UI2/CL_JSON — never manual PCRE parsing
10. BAL logging: BAL_LOG_CREATE → BAL_LOG_MSG_ADD → BAL_DB_SAVE

4. ABAP OO Pattern — Abstract Handler + Factory

CLASS zcl_handler_abstract DEFINITION PUBLIC ABSTRACT.
  PUBLIC SECTION.
    INTERFACES zif_handler.
  PROTECTED SECTION.
    METHODS handle_action ABSTRACT.
ENDCLASS.

CLASS zcl_handler_mm DEFINITION PUBLIC FINAL
  INHERITING FROM zcl_handler_abstract.
  PROTECTED SECTION.
    METHODS handle_action REDEFINITION.
ENDCLASS.

" Factory dispatch
CASE to_upper( iv_module ).
  WHEN 'MM'. ro_handler = NEW zcl_handler_mm( ).
  WHEN 'SD'. ro_handler = NEW zcl_handler_sd( ).
ENDCASE.

5. DDIC Table Design — Header + Item

• Header (ZROUTER_TMPL_HD): MANDT (key), TEMPLATE_ID (key), MODULE, ACTION, VERSION, TITLE, CREATED_BY, CREATED_AT, ACTIVE_FLAG
• Items (ZROUTER_TMPL_CD): MANDT (key), TEMPLATE_ID (key), LINE_NUM (key), CODE_LINE
• Use CHAR1 for flags (X = true), NUMC4 for version, TIMESTAMPL for UTC

6. INSERT REPORT + SUBMIT (Full Dynamic)

" Heavier — use only when you need WRITE output capture
INSERT REPORT lv_report FROM lt_source.
SUBMIT (lv_report) VIA SELECTION-SCREEN AND RETURN.
" Capture via LIST_FROM_MEMORY + LIST_TO_ASCI

Pitfalls

• GENERATE SUBROUTINE POOL line offset:
  • Cause: Error line numbers start at FORM, not PROGRAM.
  • Solution: Subtract 2 to map back to user expression line.
• BAPI_TRANSACTION_COMMIT without WAIT:
  • Cause: Update task runs async; next BAPI may read stale data.
  • Solution: Always pass wait = 'X'.
• RFC_READ_TABLE 512-char truncation:
  • Cause: Field values silently truncated beyond 512 chars.
  • Solution: Use ADT SQL or HANA query for long text fields.
• sy-subrc after BAPI call:
  • Cause: Some BAPIs return sy-subrc = 0 with BAPIRET2-TYPE = 'E'.
  • Solution: Always check BAPIRET2-TYPE, not sy-subrc.

Verification

# Lint the ABAP source
npx abaplint templates/**/*.abap

# Verify BAPI commit pattern present
grep -rn "BAPI_TRANSACTION_COMMIT" src/ | grep -c "wait.*X"

# Verify no COMMIT WORK in source
grep -rn "COMMIT WORK" src/ && echo "FAIL: found COMMIT WORK" || echo "OK"