ABAP BAdIs & Enhancements: GET BADI, CALL BADI

" Get BAdI handle
GET BADI lo_badi.

" Call BAdI
CALL BADI lo_badi->method_name
  EXPORTING param = value
  IMPORTING result = lv_result.

" 1. Find Enhancement Spot (SE18)
"    Example: BADI_SD_SALES

" 2. Create Implementation (SE19)
"    Enhancement Implementation: ZEI_SD_SALES
"    BAdI Implementation: ZBI_SD_SALES

" 3. Implementation class
CLASS zcl_sd_sales_badi DEFINITION
  PUBLIC FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES: if_badi_sd_sales.
ENDCLASS.

CLASS zcl_sd_sales_badi IMPLEMENTATION.
  METHOD if_badi_sd_sales~check_document.
    " Customer-specific check
    IF is_header-auart = 'ZOR'.
      " Special handling for order type ZOR
      IF is_header-vkorg NOT IN gt_allowed_orgs.
        ev_error = abap_true.
        ev_message = 'Order type ZOR not allowed for this sales org'.
      ENDIF.
    ENDIF.
  ENDMETHOD.

  METHOD if_badi_sd_sales~modify_data.
    " Modify data before saving
    IF cs_header-bstkd IS INITIAL.
      cs_header-bstkd = |AUTO-{ sy-datum }|.
    ENDIF.
  ENDMETHOD.
ENDCLASS.

" Find BAdI definition
DATA: lo_badi TYPE REF TO badi_sd_sales.

" Get handle
GET BADI lo_badi.

" Call method
CALL BADI lo_badi->check_document
  EXPORTING
    is_header = ls_header
  IMPORTING
    ev_error   = lv_error
    ev_message = lv_message.

IF lv_error = abap_true.
  MESSAGE lv_message TYPE 'E'.
ENDIF.

" 1. Create Enhancement Spot (SE18)
"    Name: ZES_ORDER_PROCESSING
"    Short description: Order Processing Extensions

" 2. Create BAdI Definition
"    Name: ZBADI_ORDER_CHECK
"    Interface: ZIF_ORDER_CHECK

" 3. Define interface
INTERFACE zif_order_check PUBLIC.
  METHODS: validate_order
    IMPORTING
      is_order        TYPE ty_order
    EXPORTING
      ev_valid        TYPE abap_bool
      et_messages     TYPE bapiret2_t.

  METHODS: enrich_order
    CHANGING
      cs_order TYPE ty_order.
ENDINTERFACE.

" 4. Use in your own code
CLASS zcl_order_processor DEFINITION.
  PUBLIC SECTION.
    METHODS: process_order
      IMPORTING is_order TYPE ty_order
      RAISING   zcx_order_error.
ENDCLASS.

CLASS zcl_order_processor IMPLEMENTATION.
  METHOD process_order.
    DATA: lo_badi    TYPE REF TO zbadi_order_check,
          lv_valid   TYPE abap_bool,
          lt_messages TYPE bapiret2_t.

    " Get and call BAdI
    GET BADI lo_badi.

    CALL BADI lo_badi->validate_order
      EXPORTING is_order    = is_order
      IMPORTING ev_valid    = lv_valid
                et_messages = lt_messages.

    IF lv_valid = abap_false.
      RAISE EXCEPTION TYPE zcx_order_error
        EXPORTING messages = lt_messages.
    ENDIF.

    " Enrich data
    DATA(ls_order) = is_order.
    CALL BADI lo_badi->enrich_order
      CHANGING cs_order = ls_order.

    " Further processing...
  ENDMETHOD.
ENDCLASS.

" BAdI definition with filter (SE18):
" Filter: VKORG (Sales Organization)

" Implementation for Sales Org 1000
CLASS zcl_badi_vkorg_1000 DEFINITION.
  PUBLIC SECTION.
    INTERFACES: zif_sales_badi.
ENDCLASS.

CLASS zcl_badi_vkorg_1000 IMPLEMENTATION.
  METHOD zif_sales_badi~process.
    " Logic only for Sales Org 1000
    cs_data-discount = '10.00'.
  ENDMETHOD.
ENDCLASS.

" Implementation for Sales Org 2000
CLASS zcl_badi_vkorg_2000 DEFINITION.
  PUBLIC SECTION.
    INTERFACES: zif_sales_badi.
ENDCLASS.

CLASS zcl_badi_vkorg_2000 IMPLEMENTATION.
  METHOD zif_sales_badi~process.
    " Different logic for Sales Org 2000
    cs_data-discount = '15.00'.
  ENDMETHOD.
ENDCLASS.


" Call with filter
DATA: lo_badi TYPE REF TO zbadi_sales.

GET BADI lo_badi
  FILTERS
    vkorg = lv_vkorg.    " Only matching implementation

CALL BADI lo_badi->process
  CHANGING cs_data = ls_data.

" BAdI with fallback (SE18):
" Fallback class: ZCL_DEFAULT_HANDLER

CLASS zcl_default_handler DEFINITION
  PUBLIC FINAL.

  PUBLIC SECTION.
    INTERFACES: zif_custom_badi.
ENDCLASS.

CLASS zcl_default_handler IMPLEMENTATION.
  METHOD zif_custom_badi~process.
    " Default behavior when no implementation is active
    rv_result = 'DEFAULT'.
  ENDMETHOD.
ENDCLASS.


" Call - fallback is used when no implementation is active
DATA: lo_badi TYPE REF TO zbadi_custom.

GET BADI lo_badi.

" Check if implementation exists
IF lo_badi IS BOUND.
  CALL BADI lo_badi->process
    IMPORTING rv_result = lv_result.
ENDIF.

" BAdI allows multiple implementations (Multiple Use)
" All active implementations are called

DATA: lo_badi     TYPE REF TO zbadi_validators,
      lt_messages TYPE bapiret2_t.

GET BADI lo_badi.

" All implementations are iterated
CALL BADI lo_badi->validate
  EXPORTING is_data     = ls_data
  CHANGING  ct_messages = lt_messages.

" lt_messages contains messages from all implementations
IF line_exists( lt_messages[ type = 'E' ] ).
  " At least one implementation reported an error
ENDIF.

" Implicit enhancement points in standard code
" Can be extended without modification

" In standard code exists:
" ENHANCEMENT-POINT ep_before_save SPOTS es_order.

" Own implementation (SE19):
ENHANCEMENT zei_order_enhancement.
  " Code is inserted at this point
  IF ls_order-custom_field IS INITIAL.
    ls_order-custom_field = 'DEFAULT'.
  ENDIF.
ENDENHANCEMENT.

" In standard code:
" ENHANCEMENT-SECTION es_validation SPOTS es_order.
"   " Original code
"   IF lv_amount < 0.
"     lv_error = abap_true.
"   ENDIF.
" END-ENHANCEMENT-SECTION.

" Own implementation replaces original:
ENHANCEMENT zei_validation_replacement.
  " Own code replaces original
  IF lv_amount < 0 OR lv_amount > 1000000.
    lv_error = abap_true.
  ENDIF.
ENDENHANCEMENT.

" Extension Include in RAP Behavior Definition:
" managed implementation in class zbp_i_order unique;
" with additional save
" {
"   ...
"   determination SetDefaults on save { create; }
" }

" BAdI for RAP Extensions
INTERFACE zif_rap_order_extension PUBLIC.
  METHODS: on_before_save
    CHANGING ct_orders TYPE zt_orders.

  METHODS: on_after_save
    IMPORTING it_orders TYPE zt_orders.
ENDINTERFACE.


" Call in Behavior Handler
CLASS lhc_order DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS save_modified FOR SAVE
      IMPORTING it_orders FOR CREATE order.
ENDCLASS.

CLASS lhc_order IMPLEMENTATION.
  METHOD save_modified.
    DATA: lo_badi TYPE REF TO zbadi_rap_order.

    " BAdI before save
    GET BADI lo_badi.

    DATA(lt_orders) = CORRESPONDING zt_orders( it_orders ).
    CALL BADI lo_badi->on_before_save
      CHANGING ct_orders = lt_orders.

    " Save...

    " BAdI after save
    CALL BADI lo_badi->on_after_save
      EXPORTING it_orders = lt_orders.
  ENDMETHOD.
ENDCLASS.

" Classic BAdI from SE18 (before Enhancement Spots)
DATA: lo_badi TYPE REF TO if_ex_badi_name.

" Get handle
CALL METHOD cl_exithandler=>get_instance
  CHANGING instance = lo_badi.

" Call method
IF lo_badi IS BOUND.
  CALL METHOD lo_badi->method_name
    EXPORTING param = value
    CHANGING  data  = ls_data.
ENDIF.

" Programmatically check if BAdI is active
DATA: lo_badi TYPE REF TO zbadi_test.

GET BADI lo_badi.

" Check if implementations exist
DATA(lv_has_impl) = boolc( lo_badi IS BOUND ).

" In SE19:
" - Open implementation
" - Set/remove "Active" checkbox
" - Activate

" BAdI with additional context
INTERFACE zif_context_badi PUBLIC.
  METHODS: process
    IMPORTING
      iv_context TYPE string
      is_data    TYPE ty_data
    EXPORTING
      es_result  TYPE ty_result.
ENDINTERFACE.


" Call with context for filtering
DATA: lo_badi TYPE REF TO zbadi_context.

GET BADI lo_badi
  FILTERS
    context = 'SPECIAL_CASE'.

" Only implementations for this context are called
CALL BADI lo_badi->process
  EXPORTING
    iv_context = 'SPECIAL_CASE'
    is_data    = ls_data
  IMPORTING
    es_result  = ls_result.

" Source Code Plugins for ABAP Cloud
" Defined in the Behavior Definition

" managed implementation in class zbp_i_product;
"
" define behavior for ZI_Product
" {
"   ...
"   // Extension point for partner
"   extension point productExtension;
" }

" Partner extension implements:
" enhance behavior for ZI_Product
" {
"   extend productExtension
"   {
"     determination CalculateDiscount on modify { field price; }
"   }
" }

" Classic User Exits (CMOD/SMOD)
" Included via includes

" Include ZXaaau01 for Exit EXIT_SAPMM06E_001
FORM userexit_save_document_prepare.
  " Customer-specific logic before save
  IF sy-tcode = 'ME21N'.
    " Modify purchase order header
  ENDIF.
ENDFORM.

" Find all enhancements for an object

" 1. SE84 - Repository Information System
"    Search for Enhancement Spots for the object

" 2. Search in code for:
"    - ENHANCEMENT-POINT
"    - ENHANCEMENT-SECTION
"    - GET BADI

" 3. SE18 - Search BAdI definitions
"    Where-used list shows implementations

" 4. SE19 - Display implementations
"    All active/inactive implementations

1. SE18 → Create Enhancement Spot
   - Name: ZES_MY_APPLICATION
   - Enter short description
   - Save

2. Add BAdI Definition
   - Name: ZBADI_MY_BADI
   - Create interface: ZIF_MY_BADI
   - Define methods in interface
   - Optional: Define filter
   - Optional: Specify fallback class

3. Activate Enhancement Spot

4. Include in code:
   DATA: lo_badi TYPE REF TO zbadi_my_badi.
   GET BADI lo_badi.
   CALL BADI lo_badi->my_method( ... ).

5. Create Implementation (SE19)
   - Enhancement Implementation: ZEI_MY_IMPL
   - BAdI Implementation: ZBI_MY_IMPL
   - Implementing Class: ZCL_MY_BADI_IMPL