ABAP RAP Fundamentals: RESTful ABAP Programming

Core Concepts

Business Object (BO): Business object with data and behavior
CDS View: Data model (see CDS Views)
Behavior Definition (BDEF): Declares the behavior (CRUD, Actions, Validations)
Behavior Implementation (BIL): Implements the behavior in ABAP

RAP Architecture

┌─────────────────────────────────────────────┐
│                  Fiori UI                    │
├─────────────────────────────────────────────┤
│              OData Service                   │
├─────────────────────────────────────────────┤
│         Projection Layer (C_*)               │
├─────────────────────────────────────────────┤
│         Business Object Layer (I_*)          │
│  ┌─────────────┐    ┌────────────────────┐  │
│  │ CDS View    │    │ Behavior           │  │
│  │ (Data)      │    │ Definition (BDEF)  │  │
│  └─────────────┘    └────────────────────┘  │
│                          │                   │
│              ┌───────────▼───────────┐      │
│              │ Behavior              │      │
│              │ Implementation (BIL)  │      │
│              └───────────────────────┘      │
├─────────────────────────────────────────────┤
│               Database                       │
└─────────────────────────────────────────────┘

Managed vs. Unmanaged Scenario

Aspect	Managed	Unmanaged
CRUD	Automatic by framework	Manually implemented
Transactions	Framework-controlled	Full control
Effort	Low	Higher
Flexibility	Standard operations	Full control
Recommended for	New developments	Legacy integration

Example: Managed Scenario

1. Database Table

@EndUserText.label : 'Travel'
@AbapCatalog.enhancement.category : #NOT_EXTENSIBLE
@AbapCatalog.tableCategory : #TRANSPARENT
define table ztravel {
  key client     : abap.clnt not null;
  key travel_id  : abap.numc(8) not null;
  agency_id      : abap.numc(6);
  customer_id    : abap.numc(6);
  begin_date     : abap.dats;
  end_date       : abap.dats;
  total_price    : abap.curr(16,2);
  currency_code  : abap.cuky;
  description    : abap.string(256);
  status         : abap.char(1);
  created_by     : abap.uname;
  created_at     : abap.utclong;
  last_changed_by: abap.uname;
  last_changed_at: abap.utclong;
}

2. Interface CDS View (I_*)

@AbapCatalog.sqlViewName: 'ZITRAVELV'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Travel - Interface View'

@Metadata.allowExtensions: true

define root view entity ZI_Travel
  as select from ztravel
{
  key travel_id       as TravelId,
      agency_id       as AgencyId,
      customer_id     as CustomerId,
      begin_date      as BeginDate,
      end_date        as EndDate,
      @Semantics.amount.currencyCode: 'CurrencyCode'
      total_price     as TotalPrice,
      @Semantics.currencyCode: true
      currency_code   as CurrencyCode,
      description     as Description,
      status          as Status,

      @Semantics.user.createdBy: true
      created_by      as CreatedBy,
      @Semantics.systemDateTime.createdAt: true
      created_at      as CreatedAt,
      @Semantics.user.lastChangedBy: true
      last_changed_by as LastChangedBy,
      @Semantics.systemDateTime.lastChangedAt: true
      last_changed_at as LastChangedAt
}

3. Behavior Definition (BDEF)

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

define behavior for ZI_Travel alias Travel
persistent table ztravel
lock master
authorization master ( instance )
etag master LastChangedAt
{
  // Standard operations
  create;
  update;
  delete;

  // Field mapping for database
  field ( readonly ) TravelId;
  field ( readonly ) CreatedBy, CreatedAt, LastChangedBy, LastChangedAt;

  // Automatic number assignment
  field ( numbering : managed ) TravelId;

  // Actions
  action ( features : instance ) acceptTravel result [1] $self;
  action ( features : instance ) rejectTravel result [1] $self;

  // Validations
  validation validateDates on save { field BeginDate, EndDate; }
  validation validateCustomer on save { field CustomerId; }

  // Determinations
  determination setStatusNew on modify { create; }
}

4. Behavior Implementation (BIL)

CLASS lhc_travel DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS:
      get_instance_features FOR INSTANCE FEATURES
        IMPORTING keys REQUEST requested_features FOR Travel
        RESULT result,

      acceptTravel FOR MODIFY
        IMPORTING keys FOR ACTION Travel~acceptTravel
        RESULT result,

      rejectTravel FOR MODIFY
        IMPORTING keys FOR ACTION Travel~rejectTravel
        RESULT result,

      validateDates FOR VALIDATE ON SAVE
        IMPORTING keys FOR Travel~validateDates,

      validateCustomer FOR VALIDATE ON SAVE
        IMPORTING keys FOR Travel~validateCustomer,

      setStatusNew FOR DETERMINE ON MODIFY
        IMPORTING keys FOR Travel~setStatusNew.
ENDCLASS.

CLASS lhc_travel IMPLEMENTATION.

  METHOD get_instance_features.
    " Read current data
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel)
      FAILED failed.

    " Feature control based on status
    result = VALUE #( FOR ls_travel IN lt_travel
      ( %tky = ls_travel-%tky
        %features-%action-acceptTravel = COND #(
          WHEN ls_travel-Status = 'O' THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )
        %features-%action-rejectTravel = COND #(
          WHEN ls_travel-Status = 'O' THEN if_abap_behv=>fc-o-enabled
          ELSE if_abap_behv=>fc-o-disabled
        )
      )
    ).
  ENDMETHOD.

  METHOD acceptTravel.
    " Set status to 'Accepted'
    MODIFY ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        UPDATE FIELDS ( Status )
        WITH VALUE #( FOR key IN keys
          ( %tky   = key-%tky
            Status = 'A' ) )
      FAILED failed
      REPORTED reported.

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

  METHOD rejectTravel.
    MODIFY ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        UPDATE FIELDS ( Status )
        WITH VALUE #( FOR key IN keys
          ( %tky   = key-%tky
            Status = 'X' ) )
      FAILED failed
      REPORTED reported.

    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        ALL FIELDS
        WITH CORRESPONDING #( keys )
      RESULT result.
  ENDMETHOD.

  METHOD validateDates.
    " Read data
    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).
      " End date must be after begin date
      IF ls_travel-EndDate < ls_travel-BeginDate.
        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.

      " Begin date must not be in the past
      IF ls_travel-BeginDate < cl_abap_context_info=>get_system_date( ).
        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-BeginDate = if_abap_behv=>mk-on
        ) TO failed-travel.

        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-BeginDate = if_abap_behv=>mk-on
          %msg = new_message_with_text(
            severity = if_abap_behv_message=>severity-error
            text     = 'Begin date must not be in the past'
          )
        ) TO reported-travel.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD validateCustomer.
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( CustomerId )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    " Validate customer
    LOOP AT lt_travel INTO DATA(ls_travel).
      IF ls_travel-CustomerId IS INITIAL.
        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-CustomerId = if_abap_behv=>mk-on
        ) TO failed-travel.

        APPEND VALUE #(
          %tky = ls_travel-%tky
          %element-CustomerId = if_abap_behv=>mk-on
          %msg = new_message_with_text(
            severity = if_abap_behv_message=>severity-error
            text     = 'Customer is required'
          )
        ) TO reported-travel.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

  METHOD setStatusNew.
    " Set status to 'Open' on create
    READ ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_travel).

    MODIFY ENTITIES OF zi_travel IN LOCAL MODE
      ENTITY Travel
        UPDATE FIELDS ( Status )
        WITH VALUE #( FOR ls_travel IN lt_travel
          WHERE ( Status IS INITIAL )
          ( %tky   = ls_travel-%tky
            Status = 'O' ) )
      REPORTED reported.
  ENDMETHOD.

ENDCLASS.

5. Projection View (C_*)

@EndUserText.label: 'Travel - Projection View'
@AccessControl.authorizationCheck: #CHECK
@Metadata.allowExtensions: true
@Search.searchable: true

define root view entity ZC_Travel
  provider contract transactional_query
  as projection on ZI_Travel
{
  key TravelId,

      @Search.defaultSearchElement: true
      @Search.fuzzinessThreshold: 0.8
      AgencyId,

      @Search.defaultSearchElement: true
      CustomerId,

      BeginDate,
      EndDate,
      TotalPrice,
      CurrencyCode,

      @Search.defaultSearchElement: true
      Description,

      @ObjectModel.text.element: ['StatusText']
      Status,
      _StatusText.Text as StatusText : localized,

      CreatedBy,
      CreatedAt,
      LastChangedBy,
      LastChangedAt
}

6. Projection Behavior Definition

projection;
strict ( 2 );

define behavior for ZC_Travel alias Travel
{
  use create;
  use update;
  use delete;

  use action acceptTravel;
  use action rejectTravel;
}

7. Service Definition

@EndUserText.label: 'Travel Service Definition'
define service ZUI_TRAVEL_O4 {
  expose ZC_Travel as Travel;
}

8. Service Binding

- Name: ZUI_TRAVEL_O4
- Binding Type: OData V4 - UI
- Service Definition: ZUI_TRAVEL_O4

EML – Entity Manipulation Language

" === READ ENTITIES ===
READ ENTITIES OF zi_travel
  ENTITY Travel
    FIELDS ( TravelId AgencyId Status )
    WITH VALUE #( ( TravelId = '00000001' ) )
  RESULT DATA(lt_travel)
  FAILED DATA(failed)
  REPORTED DATA(reported).


" === MODIFY ENTITIES - Create ===
MODIFY ENTITIES OF zi_travel
  ENTITY Travel
    CREATE FIELDS ( AgencyId CustomerId BeginDate EndDate )
    WITH VALUE #( (
      %cid       = 'CID_1'
      AgencyId   = '000001'
      CustomerId = '000010'
      BeginDate  = cl_abap_context_info=>get_system_date( )
      EndDate    = cl_abap_context_info=>get_system_date( ) + 7
    ) )
  MAPPED DATA(mapped)
  FAILED failed
  REPORTED reported.


" === MODIFY ENTITIES - Update ===
MODIFY ENTITIES OF zi_travel
  ENTITY Travel
    UPDATE FIELDS ( Status Description )
    WITH VALUE #( (
      TravelId    = '00000001'
      Status      = 'A'
      Description = 'Updated'
    ) )
  FAILED failed
  REPORTED reported.


" === MODIFY ENTITIES - Delete ===
MODIFY ENTITIES OF zi_travel
  ENTITY Travel
    DELETE FROM VALUE #( ( TravelId = '00000001' ) )
  FAILED failed
  REPORTED reported.


" === MODIFY ENTITIES - Execute Action ===
MODIFY ENTITIES OF zi_travel
  ENTITY Travel
    EXECUTE acceptTravel FROM VALUE #( ( TravelId = '00000001' ) )
  FAILED failed
  REPORTED reported.


" === COMMIT ENTITIES ===
COMMIT ENTITIES
  RESPONSE OF zi_travel
    FAILED DATA(commit_failed)
    REPORTED DATA(commit_reported).

Behavior Elements

Actions

" Instance action (on a single row)
action acceptTravel result [1] $self;

" Static action (without instance)
static action createFromTemplate result [1] $self;

" Factory action (creates new instance)
factory action copyTravel [1];

" With parameters
action setStatus parameter ZA_StatusParameter result [1] $self;

Validations

" On save
validation validateDates on save { field BeginDate, EndDate; }

" On modify (immediate validation)
validation validatePrice on modify { field TotalPrice; }

" Draft validations
draft validation validateConsistency on save;

Determinations

" On create
determination setDefaults on modify { create; }

" On field change
determination calculateTotal on modify { field Quantity, Price; }

" On save
determination generateNumber on save { create; }

Feature Control

" Global features
field ( readonly ) TravelId;
field ( mandatory ) CustomerId;
field ( readonly : update ) AgencyId;

" Instance features (dynamic)
action ( features : instance ) acceptTravel;

Draft Handling

managed implementation in class zbp_i_travel unique;
strict ( 2 );
with draft;

define behavior for ZI_Travel alias Travel
persistent table ztravel
draft table zdraft_travel
lock master
total etag LastChangedAt
authorization master ( instance )
etag master LastChangedAt
{
  create;
  update;
  delete;

  // Draft actions (automatically available)
  draft action Edit;
  draft action Activate optimized;
  draft action Discard;
  draft action Resume;
  draft determine action Prepare;
}

Important Classes

Class	Description
`cl_abap_behavior_handler`	Base class for Behavior Implementation
`cl_abap_context_info`	System context (date, user)
`if_abap_behv`	Constants (fc-o-enabled, mk-on)
`if_abap_behv_message`	Message severity

Important Notes / Best Practices

Managed scenario for new developments – framework handles CRUD.
Interface Views (I_*) for data model, Projection Views (C_*) for UI/API.
EML (Entity Manipulation Language) for programmatic BO access.
Validations for business rules, Determinations for automatic values.
Actions for business operations beyond CRUD.
Feature Control for dynamic field/action availability.
Draft for intermediate storage during complex input.
Use IN LOCAL MODE for access without authorization check.
FAILED and REPORTED for error handling and messages.
Strict Mode (strict ( 2 )) for best-practice validation.
Combine with CDS Views for the data model.