RAP Managed vs Unmanaged: When to Use Which Scenario?

" Who performs CREATE, UPDATE, DELETE?

" Managed: "SAP, you do it!"
managed implementation in class zbp_i_travel unique;

" Unmanaged: "I'll do it myself!"
unmanaged implementation in class zbp_i_travel unique;

managed implementation in class zbp_i_travel unique;
strict ( 2 );
with draft;  " Draft only available in Managed!

define behavior for ZI_Travel alias Travel
persistent table ztravel      " Framework writes here automatically
draft table zdraft_travel     " For draft data
lock master                   " Framework manages locks
total etag LastChangedAt      " Optimistic locking via ETag
authorization master ( instance )
{
  // CRUD: Only declare, no implementation needed!
  create;
  update;
  delete;

  // Fields: Framework handles mapping
  field ( readonly ) TravelId;
  field ( readonly ) CreatedBy, CreatedAt, LastChangedBy, LastChangedAt;
  field ( numbering : managed ) TravelId;  " Auto number assignment!

  // Business logic: Implement here
  validation validateDates on save { field BeginDate, EndDate; }
  determination setStatusNew on modify { create; }
  action acceptTravel result [1] $self;

  // Draft Actions: Framework provides them automatically
  draft action Edit;
  draft action Activate optimized;
  draft action Discard;
  draft action Resume;

  // Associations
  association _Bookings { create; with draft; }
}

define behavior for ZI_Booking alias Booking
persistent table zbooking
draft table zdraft_booking
lock dependent by _Travel      " Lock from parent
authorization dependent by _Travel
{
  update;
  delete;

  field ( readonly ) TravelId, BookingId;
  field ( numbering : managed ) BookingId;

  association _Travel { with draft; }
}

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS:
      " Only implement business logic!

      " Validation: Executed on save
      validateDates FOR VALIDATE ON SAVE
        IMPORTING keys FOR Travel~validateDates,

      " Determination: Set automatic values
      setStatusNew FOR DETERMINE ON MODIFY
        IMPORTING keys FOR Travel~setStatusNew,

      " Action: Business operation
      acceptTravel FOR MODIFY
        IMPORTING keys FOR ACTION Travel~acceptTravel RESULT result.

    " DO NOT implement: get_global_authorizations, read, create, update, delete
    " -> Framework does this automatically!
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.

  METHOD validateDates.
    " Framework has ALREADY read data -> only validate
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( BeginDate EndDate )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    LOOP AT lt_travel INTO DATA(ls_travel).
      " Check business rule
      IF ls_travel-EndDate < ls_travel-BeginDate.
        " Fill framework structure for errors
        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-EndDate = if_abap_behv=>mk-on
        ) TO failed-travel.

        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-EndDate = if_abap_behv=>mk-on
          %msg = new_message_with_text(
            severity = if_abap_behv_message=>severity-error
            text     = 'End date must be after begin date'
          )
        ) TO reported-travel.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD setStatusNew.
    " Framework has created entity -> set default values
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    " Only set new ones (initial status) to 'O' (Open)
    MODIFY ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        UPDATE FIELDS ( Status )
        WITH VALUE #( FOR travel IN lt_travel WHERE ( Status IS INITIAL )
          ( %tky   = travel-%tky
            Status = 'O' ) )
      REPORTED DATA(reported_modify).
  ENDMETHOD.

  METHOD acceptTravel.
    " Action = Business operation (not just an update)
    MODIFY ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        UPDATE FIELDS ( Status LastChangedAt )
        WITH VALUE #( FOR key IN keys
          ( %tky          = key-%tky
            Status        = 'A'
            LastChangedAt = cl_abap_context_info=>get_system_date( ) ) )
      FAILED failed
      REPORTED reported.

    " Return result (result [1] $self)
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        ALL FIELDS
        WITH CORRESPONDING #( keys )
      RESULT result.
  ENDMETHOD.

ENDCLASS.

unmanaged implementation in class zbp_i_travel unique;
strict ( 2 );

define behavior for ZI_Travel alias Travel
lock master
authorization master ( instance )
etag master LastChangedAt
{
  // CRUD: Everything must be implemented!
  create;
  update;
  delete;

  // Read MUST also be implemented (unlike Managed!)

  // Business logic like in Managed
  validation validateDates on save { field BeginDate, EndDate; }
  determination setStatusNew on modify { create; }
  action acceptTravel result [1] $self;

  // Lock handling must be implemented by YOU
  lock ( lock_key );
}

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS:
      " Implement EVERYTHING yourself:

      " Create: Create new entities
      create FOR MODIFY
        IMPORTING entities FOR CREATE Travel,

      " Update: Modify existing entities
      update FOR MODIFY
        IMPORTING entities FOR UPDATE Travel,

      " Delete: Delete entities
      delete FOR MODIFY
        IMPORTING keys FOR DELETE Travel,

      " Read: Read entities
      read FOR READ
        IMPORTING keys FOR READ Travel RESULT result,

      " Lock: Manage locks
      lock FOR LOCK
        IMPORTING keys FOR LOCK Travel,

      " Feature Control
      get_instance_features FOR INSTANCE FEATURES
        IMPORTING keys REQUEST requested_features FOR Travel RESULT result,

      " Business logic (like in Managed)
      validateDates FOR VALIDATE ON SAVE
        IMPORTING keys FOR Travel~validateDates,

      setStatusNew FOR DETERMINE ON MODIFY
        IMPORTING keys FOR Travel~setStatusNew,

      acceptTravel FOR MODIFY
        IMPORTING keys FOR ACTION Travel~acceptTravel RESULT result.
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.

  METHOD create.
    " Extract data from entities parameter
    DATA lt_travel TYPE TABLE FOR CREATE zi_travel.
    lt_travel = entities.

    " Number assignment (MANUAL, since unmanaged!)
    LOOP AT lt_travel ASSIGNING FIELD-SYMBOL(<fs_travel>).
      " Get number from number range
      TRY.
          <fs_travel>-TravelId = cl_numberrange_runtime=>get_next_number(
            nr_range_nr = '01'
            object      = 'ZTRAVEL'
          ).
        CATCH cx_number_ranges INTO DATA(lx_nr).
          " Handle error
          APPEND VALUE #(
            %cid      = <fs_travel>-%cid
            %fail-cause = if_abap_behv=>cause-unspecific
          ) TO failed-travel.
          CONTINUE.
      ENDTRY.

      " Set defaults
      <fs_travel>-CreatedBy = sy-uname.
      <fs_travel>-CreatedAt = cl_abap_context_info=>get_system_date( ).
      <fs_travel>-Status    = 'O'.

      " Write to DB (MANUAL!)
      INSERT ztravel FROM @( CORRESPONDING #( <fs_travel> ) ).

      IF sy-subrc = 0.
        " Return successful mapping
        APPEND VALUE #(
          %cid    = <fs_travel>-%cid
          TravelId = <fs_travel>-TravelId
        ) TO mapped-travel.
      ELSE.
        " Error
        APPEND VALUE #(
          %cid = <fs_travel>-%cid
          %fail-cause = if_abap_behv=>cause-unspecific
        ) TO failed-travel.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD update.
    " Extract fields to update
    LOOP AT entities INTO DATA(ls_entity).
      " %control checks which fields should be changed
      IF ls_entity-%control-Status = if_abap_behv=>mk-on.
        " Status was changed -> DB update
        UPDATE ztravel
          SET status = @ls_entity-Status,
              last_changed_by = @sy-uname,
              last_changed_at = @cl_abap_context_info=>get_system_date( )
          WHERE travel_id = @ls_entity-TravelId.

        IF sy-subrc <> 0.
          APPEND VALUE #(
            %tky = ls_entity-%tky
            %fail-cause = if_abap_behv=>cause-not_found
          ) TO failed-travel.
        ENDIF.
      ENDIF.

      " Handle additional fields similarly...
      IF ls_entity-%control-Description = if_abap_behv=>mk-on.
        UPDATE ztravel SET description = @ls_entity-Description
          WHERE travel_id = @ls_entity-TravelId.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD delete.
    " Delete from DB
    DELETE FROM ztravel
      WHERE travel_id IN ( SELECT TravelId FROM @keys AS k ).

    IF sy-dbcnt < lines( keys ).
      " Not all deleted -> error
      LOOP AT keys INTO DATA(ls_key).
        SELECT SINGLE @abap_true FROM ztravel
          WHERE travel_id = @ls_key-TravelId
          INTO @DATA(lv_exists).

        IF lv_exists = abap_true.
          " Still exists -> could not be deleted
          APPEND VALUE #(
            %tky = ls_key-%tky
            %fail-cause = if_abap_behv=>cause-locked
          ) TO failed-travel.
        ENDIF.
      ENDLOOP.
    ENDIF.
  ENDMETHOD.

  METHOD read.
    " Read data from DB
    SELECT * FROM ztravel
      FOR ALL ENTRIES IN @keys
      WHERE travel_id = @keys-TravelId
      INTO TABLE @DATA(lt_db_travel).

    " Convert to RAP structure
    result = CORRESPONDING #( lt_db_travel MAPPING TO ENTITY ).
  ENDMETHOD.

  METHOD lock.
    " Lock the lock object (via ENQUEUE)
    LOOP AT keys INTO DATA(ls_key).
      CALL FUNCTION 'ENQUEUE_EZTRAVEL'
        EXPORTING
          mode_ztravel = 'E'
          mandt        = sy-mandt
          travel_id    = ls_key-TravelId
        EXCEPTIONS
          foreign_lock = 1
          system_failure = 2
          OTHERS       = 3.

      IF sy-subrc <> 0.
        " Lock failed
        APPEND VALUE #(
          %tky = ls_key-%tky
          %fail-cause = if_abap_behv=>cause-locked
        ) TO failed-travel.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD get_instance_features.
    " Feature Control (like in Managed)
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    result = VALUE #( FOR travel IN lt_travel
      ( %tky = travel-%tky
        %features-%action-acceptTravel = COND #(
          WHEN travel-Status = 'O' THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )
      )
    ).
  ENDMETHOD.

  METHOD validateDates.
    " Identical to Managed
    " ... (see Managed example above)
  ENDMETHOD.

  METHOD setStatusNew.
    " Identical to Managed
    " ... (see Managed example above)
  ENDMETHOD.

  METHOD acceptTravel.
    " Identical to Managed
    " ... (see Managed example above)
  ENDMETHOD.

ENDCLASS.

managed implementation in class zbp_i_travel unique;
strict ( 2 );
with additional save;  " <- Activate hook

define behavior for ZI_Travel alias Travel
persistent table ztravel
{
  create;
  update;
  delete;
  // ...
}

CLASS lsc_travel DEFINITION INHERITING FROM cl_abap_behavior_saver.
  PROTECTED SECTION.
    METHODS:
      " save_modified: AFTER framework save, BEFORE final COMMIT
      save_modified REDEFINITION,

      " cleanup_finalize: AFTER COMMIT (or ROLLBACK)
      cleanup_finalize REDEFINITION.
ENDCLASS.

CLASS lsc_travel IMPLEMENTATION.

  METHOD save_modified.
    " Framework has ALREADY written to DB (but not yet committed)
    " Now you can implement side effects:

    " Example: Send email for each new Travel
    IF create-travel IS NOT INITIAL.
      LOOP AT create-travel INTO DATA(ls_created).
        " Call email API (see /en/email-sending/)
        TRY.
            cl_email_sender=>send_notification(
              recipient = '[email protected]'
              subject   = |New travel { ls_created-TravelId } created|
              body      = |Travel from { ls_created-BeginDate } to { ls_created-EndDate }|
            ).
          CATCH cx_send_req_bcs INTO DATA(lx_email).
            " Log error, but DO NOT abort transaction
            cl_bali_log=>create( )->add_item( cl_bali_message_setter=>create_from_exception( lx_email ) )->save( ).
        ENDTRY.
      ENDLOOP.
    ENDIF.

    " Example: Call external API for updates
    IF update-travel IS NOT INITIAL.
      LOOP AT update-travel INTO DATA(ls_updated).
        " HTTP call to external system (see /en/http-client/)
        DATA(lo_http) = cl_web_http_client_manager=>create_by_http_destination( ... ).
        " ... send HTTP request
      ENDLOOP.
    ENDIF.
  ENDMETHOD.

  METHOD cleanup_finalize.
    " AFTER COMMIT or ROLLBACK
    " Here you can implement cleanup logic
    " (e.g., delete temporary files, close connections)
  ENDMETHOD.

ENDCLASS.

+--------------------------------------------------+
| New application (Greenfield)?                     |
+---+------------------------------------------+----+
    | Yes                                      | No
    v                                          v
+------------------------------+    +------------------------------+
| Standard CRUD sufficient?    |    | Integrate legacy system?     |
+---+-----------------------+--+    +---+-----------------------+--+
    | Yes                   | No        | Yes                   | No
    v                       v           v                       v
+----------+    +--------------+  +----------+    +--------------+
| MANAGED  |    | Complex DB   |  |UNMANAGED |    | Special      |
|          |    | operations?  |  |          |    | transaction? |
+----------+    +---+------+---+  +----------+    +---+------+---+
                    | Yes  | No                       | Yes  | No
                    v      v                          v      v
            +----------+ +------------+       +----------+ +----------+
            |UNMANAGED | | MANAGED +  |       |UNMANAGED | | MANAGED  |
            |          | |save_modified|       |          | |          |
            +----------+ +------------+       +----------+ +----------+

" Before:
unmanaged implementation in class zbp_i_travel unique;

" After:
managed implementation in class zbp_i_travel unique;

" Additionally:
define behavior for ZI_Travel alias Travel
persistent table ztravel  " <- Add
// draft table zdraft_travel  <- Optional: Activate draft
lock master
{
  create;
  update;
  delete;

  field ( numbering : managed ) TravelId;  " <- Instead of manual number assignment
  // ...
}

" Before (Unmanaged): All methods
CLASS lhc_travel DEFINITION ...
  METHODS:
    create FOR MODIFY ...,
    update FOR MODIFY ...,
    delete FOR MODIFY ...,
    read FOR READ ...,
    lock FOR LOCK ...,
    validateDates FOR VALIDATE ...,
    // etc.

" After (Managed): Keep only business logic
CLASS lhc_travel DEFINITION ...
  METHODS:
    " create, update, delete, read, lock -> DELETE!
    " Only business logic:
    validateDates FOR VALIDATE ...,
    setStatusNew FOR DETERMINE ...,
    acceptTravel FOR MODIFY ...

" Before (Unmanaged):
METHOD create.
  INSERT ztravel FROM @( CORRESPONDING #( entities ) ).
  " ...
ENDMETHOD.

" After (Managed): Delete method completely!
" Framework does INSERT automatically

" Before (Unmanaged):
<fs_travel>-TravelId = cl_numberrange_runtime=>get_next_number( ... ).

" After (Managed):
" In BDEF: field ( numbering : managed ) TravelId;
" -> Framework assigns automatically from `persistent table ztravel` key sequence