Sap Rap Comprehensive

SAP RAP — RESTful Application Programming Model

Related Skills

• sap-s4hana-extensibility — Extending standard SAP RAP BOs
• sap-security-authorization — RAP authorization patterns
• sap-testing-quality — RAP test doubles in depth

Quick Start

RAP BO in 5 artifacts:

1. Database Table     → ZTAB_TRAVEL
2. CDS View Entity    → ZI_Travel (interface, root)
3. Behavior Definition → ZI_Travel (managed, draft)
4. Behavior Impl.     → ZBP_I_Travel (handler + saver)
5. Service Definition  → ZSD_Travel → Service Binding (V4)

Minimum BDEF (managed with draft):

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

define behavior for ZI_Travel alias Travel
persistent table ztab_travel
draft table zdraft_travel
etag master LocalLastChangedAt
lock master total etag LastChangedAt
authorization master ( global, instance )
{
  field ( readonly ) TravelUUID;
  field ( mandatory ) AgencyID, CustomerID;

  create; update; delete;

  determination SetStatusNew on modify { create; }
  validation ValidateDates on save { field BeginDate, EndDate; }
  action ( features : instance ) AcceptTravel result [1] $self;

  draft action Resume;
  draft action Edit;
  draft action Activate optimized;
  draft action Discard;
  draft determine action Prepare;

  mapping for ztab_travel corresponding;
}

Core Concepts

RAP Architecture Layers

┌─ Service Layer ──────────────────────────────┐
│  Service Definition → Service Binding (V2/V4) │
├─ BO Projection Layer ────────────────────────┤
│  CDS Projection View (C_*) + Projection BDEF  │
├─ BO Interface Layer ─────────────────────────┤
│  CDS View Entity (I_*) + Behavior Definition   │
│  + Behavior Implementation (Handler/Saver)     │
├─ Data Layer ─────────────────────────────────┤
│  Database Tables / CDS Abstract Entities       │
└──────────────────────────────────────────────┘

Implementation Types

CDS View Entity — Root with Child

@AccessControl.authorizationCheck: #CHECK
define root view entity ZI_Travel
  as select from ztab_travel
  composition [0..*] of ZI_Booking as _Booking
{
  key travel_uuid       as TravelUUID,
      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,
      currency_code     as CurrencyCode,
      overall_status    as OverallStatus,
      @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,
      @Semantics.systemDateTime.localInstanceLastChangedAt: true
      local_last_changed_at as LocalLastChangedAt,

      _Booking
}

Common Patterns

Pattern 1: Validation (on save)

METHOD validateDates.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
    FIELDS ( BeginDate EndDate )
    WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travels).

  LOOP AT lt_travels INTO DATA(ls_travel).
    IF ls_travel-BeginDate > ls_travel-EndDate.
      APPEND VALUE #( %tky = ls_travel-%tky ) TO failed-travel.
      APPEND VALUE #( %tky = ls_travel-%tky
        %msg = new_message_with_text(
          severity = if_abap_behv_message=>severity-error
          text     = 'Begin date must be before end date' )
        %element-BeginDate = if_abap_behv=>mk-on
        %element-EndDate   = if_abap_behv=>mk-on
      ) TO reported-travel.
    ENDIF.
  ENDLOOP.
ENDMETHOD.

Pattern 2: Determination (on modify)

METHOD setStatusNew.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
    FIELDS ( OverallStatus )
    WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travels).

  MODIFY ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
    UPDATE FIELDS ( OverallStatus )
    WITH VALUE #( FOR travel IN lt_travels
      WHERE ( OverallStatus IS INITIAL )
      ( %tky = travel-%tky  OverallStatus = 'O' ) ).  " Open
ENDMETHOD.

Pattern 3: Action with Result

METHOD acceptTravel.
  MODIFY ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
    UPDATE FIELDS ( OverallStatus )
    WITH VALUE #( FOR key IN keys
      ( %tky = key-%tky  OverallStatus = 'A' ) ).  " Accepted

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

  result = VALUE #( FOR travel IN lt_travels
    ( %tky = travel-%tky  %param = travel ) ).
ENDMETHOD.

Pattern 4: Instance Feature Control

METHOD get_instance_features.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel
    FIELDS ( OverallStatus )
    WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travels).

  result = VALUE #( FOR travel IN lt_travels
    ( %tky = travel-%tky
      %action-AcceptTravel = COND #(
        WHEN travel-OverallStatus = 'A'
        THEN if_abap_behv=>fc-o-disabled    " Already accepted
        ELSE if_abap_behv=>fc-o-enabled )
      %action-RejectTravel = COND #(
        WHEN travel-OverallStatus = 'X'
        THEN if_abap_behv=>fc-o-disabled    " Already rejected
        ELSE if_abap_behv=>fc-o-enabled )
    ) ).
ENDMETHOD.

Pattern 5: Authorization (Global + Instance)

" Global authorization: Can user create at all?
METHOD get_global_authorizations.
  IF requested_authorizations-%create = if_abap_behv=>mk-on.
    AUTHORITY-CHECK OBJECT 'Z_TRAVEL' ID 'ACTVT' FIELD '01'.
    result-%create = COND #(
      WHEN sy-subrc = 0 THEN if_abap_behv=>auth-allowed
      ELSE if_abap_behv=>auth-unauthorized ).
  ENDIF.
ENDMETHOD.

" Instance authorization: Can user update THIS travel?
METHOD get_instance_authorizations.
  READ ENTITIES OF zi_travel IN LOCAL MODE
    ENTITY Travel FIELDS ( AgencyID ) WITH CORRESPONDING #( keys )
    RESULT DATA(lt_travels).

  LOOP AT lt_travels INTO DATA(ls_travel).
    AUTHORITY-CHECK OBJECT 'Z_TRAVEL'
      ID 'ACTVT' FIELD '02'
      ID 'Z_AGNCY' FIELD ls_travel-AgencyID.
    DATA(lv_update) = COND #(
      WHEN sy-subrc = 0 THEN if_abap_behv=>auth-allowed
      ELSE if_abap_behv=>auth-unauthorized ).

    APPEND VALUE #( %tky = ls_travel-%tky
      %update = lv_update
      %action-AcceptTravel = lv_update
    ) TO result.
  ENDLOOP.
ENDMETHOD.

Pattern 6: EML (Entity Manipulation Language)

" Create
MODIFY ENTITIES OF zi_travel
  ENTITY Travel
  CREATE FIELDS ( AgencyID CustomerID BeginDate EndDate )
  WITH VALUE #( (
    %cid       = 'CID_1'
    AgencyID   = '70001'
    CustomerID = '100000'
    BeginDate  = cl_abap_context_info=>get_system_date( )
    EndDate    = cl_abap_context_info=>get_system_date( ) + 14
  ) )
  MAPPED DATA(ls_mapped)
  FAILED DATA(ls_failed)
  REPORTED DATA(ls_reported).

" Read
READ ENTITIES OF zi_travel
  ENTITY Travel
  ALL FIELDS
  WITH VALUE #( ( TravelUUID = lv_uuid ) )
  RESULT DATA(lt_result).

" Commit
COMMIT ENTITIES
  RESPONSE OF zi_travel
  FAILED DATA(ls_commit_failed)
  REPORTED DATA(ls_commit_reported).

Pattern 7: Draft Handling Flow

[New]
  → Edit → [Draft created in draft table]
    → Modify fields (auto-saved to draft table)
      → Prepare (runs validations on draft)
        → Activate (moves draft → active table, runs on-save validations)

[Existing Active]
  → Edit → [Copy to draft table, lock active]
    → Modify → Prepare → Activate

[Discard] → Delete draft, unlock active
[Resume] → Continue editing existing draft

Draft table structure: Same as active table + admin fields (%is_draft, draftentityoperationcode, etc.)

Error Catalog

Performance Tips

• Use IN LOCAL MODE in handler methods to skip authorization re-checks
• Read only needed fields: FIELDS ( Field1 Field2 ) not ALL FIELDS
• Avoid N+1 queries: batch-read entities, don't loop-and-read
• Use %control to detect which fields were actually sent by the client
• Keep validations focused: one validation per business rule
• Use on modify determinations for immediate feedback, on save for expensive checks

BTP vs S/4HANA Differences

Bundled Resources

Gotchas

• Managed vs. Unmanaged save: Managed RAP handles INSERT/UPDATE/DELETE automatically; if you need custom save logic, use managed with additional save or managed with unmanaged save — don't fight the framework
• Draft and non-draft mismatch: If root entity has draft, ALL compositions in the BO must also have draft — partial draft is not allowed
• EML in non-RAP context: EML (MODIFY ENTITIES OF ...) can only be used inside RAP behavior implementations or with IN LOCAL MODE / PRIVILEGED ACCESS — not in arbitrary ABAP programs
• Late numbering gotcha: With late numbering, %pid (preliminary ID) is only valid within the same LUW — never persist it; map to final key in adjust_numbers
• Authorization timing: Global authorization is checked FIRST, then instance authorization — if global auth fails, instance auth never runs
• CDS view vs. view entity: RAP requires CDS view ENTITIES (define root view entity), not classic CDS views (define view) — migration needed for legacy CDS
• Determination on modify vs. on save: on modify runs immediately and can set fields visible to user; on save runs during finalize — choose based on UX needs
• Strict mode levels: strict(2) is recommended for new BOs; it enforces additional validations and will be required in future releases

Validation Workflow

After creating or modifying a RAP BO, validate completeness:

bash scripts/validate-rap-bo.sh ./src

RAP BO checklist:

• Root view entity defined with define root view entity
• BDEF has authorization control (master/dependent)
• ETag field defined for concurrency control
• Draft table defined (if draft enabled)
• Service definition and binding created
• At least one unit test class exists

MCP Server Integration

{
  "mcpServers": {
    "vibing-steampunk": {
      "command": "npx", "args": ["-y", "vibing-steampunk"],
      "env": { "SAP_HOST": "https://your-system.abap.hana.ondemand.com",
               "SAP_USER": "YOUR_USER", "SAP_PASSWORD": "YOUR_PASSWORD" }
    }
  }
}

• Vibing Steampunk: Read/write BDEF, CDS, handler classes directly on SAP system via ADT

Source Documentation

• SAP Help: RAP
• GitHub: SAP ABAP Cheat Sheets — RAP
• GitHub: RAP Generator
• SAP RAP Developer Guide
• GitHub: RAP Workshops (RAP100-640)