ABAP RESTful Application Programming Model (RAP) Samples

A Service Consumption Model is an ABAP repository object that allows you to consume remote services (currently supporting OData and SOAP). It uses an external interface description (like an OData $metadata file or a WSDL) to automatically generate repository objects, including a Service Definition and an Abstract Entity. These generated objects (OData Client proxies or SOAP proxies) enable you to write ABAP code to interact with remote services.

To create one:

1. In ADT, right-click your package and select New > Other ABAP Repository Object.
2. Search for and select Service Consumption Model.
3. In the wizard, provide a name (e.g., ZSC_RAP_AGENCY_####) and set the Remote Consumption Model to OData.
4. Upload the downloaded $metadata XML file.
5. Provide a Prefix (e.g., RAP_####) to influence the naming of the generated abstract entities.
6. Review the generated ABAP Artifact Name and the list of objects to be created (Service Definition and Abstract Entity).
7. Complete the wizard by selecting a transport request.

Generated Objects:
- Service Consumption Model: ZSC_RAP_AGENCY_####
- Service Definition: ZSC_RAP_AGENCY_####
- Abstract Entity: ZRAP_####Z_TRAVEL_AGENCY_ES5

To transform a standard CDS data model into a Business Object (BO) structure capable of transactional behavior, you must define a composition tree (parent-child relationship).

1. Define the Root Node (Parent)

In the parent CDS view (e.g., ZI_RAP_Travel_####), change the definition to a root view and replace the standard association to the child with a composition:

define root view entity ZI_RAP_Travel_####
  ... 
  composition [0..*] of ZI_RAP_Booking_#### as _Booking

2. Define the Child Node

In the child CDS view (e.g., ZI_RAP_Booking_####), replace the standard association to the parent with an association to parent:

association to parent ZI_RAP_Travel_#### as _Travel on $projection.TravelUUID = _Travel.TravelUUID

3. Activation

After modifying both files, use Activate All (Ctrl+Shift+F3) to activate both the parent and child views simultaneously.

// In Parent (Travel)
define root view entity ZI_RAP_Travel_####
  composition [0..*] of ZI_RAP_Booking_#### as _Booking

// In Child (Booking)
association to parent ZI_RAP_Travel_#### as _Travel on $projection.TravelUUID = _Travel.TravelUUID

The select method is responsible for handling incoming OData requests and providing the corresponding data and metadata to the RAP framework.

Key Request Objects and Methods:

• io_request: Used to retrieve OData-specific query parameters.
  • io_request->get_paging()->get_page_size(): Retrieves the number of records requested (top).
  • io_request->get_paging()->get_offset(): Retrieves the starting position (skip).
  • io_request->get_filter()->get_as_ranges(): Retrieves the filter conditions as ranges.
  • io_request->is_data_requested(): Returns true if the client requested business data.
  • io_request->is_total_numb_of_rec_requested(): Returns true if the client requested a $count.

Key Response Requirements:

• io_response->set_data( ... ): Mandatory if is_data_requested() is true. This passes the retrieved business data back to the framework.
• io_response->set_total_number_of_records( ... ): Required if is_total_numb_of_rec_requested() is true. This sets the total count of entities.

METHOD if_rap_query_provider~select.
    DATA business_data TYPE t_business_data.
    DATA(top)     = io_request->get_paging( )->get_page_size( ).
    DATA(skip)    = io_request->get_paging( )->get_offset( ).
    DATA(requested_fields)  = io_request->get_requested_elements( ).
    DATA(sort_order)    = io_request->get_sort_elements( ).
    DATA count TYPE int8.
    TRY.
        DATA(filter_condition) = io_request->get_filter( )->get_as_ranges( ).

        get_agencies(
                 EXPORTING
                   filter_cond        = filter_condition
                   top                = CONV i( top )
                   skip               = CONV i( skip )
                   is_data_requested  = io_request->is_data_requested( )
                   is_count_requested = io_request->is_total_numb_of_rec_requested( )
                 IMPORTING
                   business_data  = business_data
                   count     = count
                 ) .

        IF io_request->is_total_numb_of_rec_requested(  ).
          io_response->set_total_number_of_records( count ).
        ENDIF.
        IF io_request->is_data_requested(  ).
          io_response->set_data( business_data ).
        ENDIF.

      CATCH cx_root INTO DATA(exception).
        DATA(exception_message) = cl_message_helper=>get_latest_t100_exception( exception )->if_message~get_longtext( ).
    ENDTRY.
  ENDMETHOD.

When defining a CDS projection view, use the following annotations to control behavior and UI capabilities:

View-Level Annotations

• @Metadata.allowExtensions: true: Enables the use of separate Metadata Extension (MDE) files to keep the CDS view clean.
• @Search.searchable: true: Enables full-text (freestyle) search capabilities for the view.
• @AccessControl.authorizationCheck: #CHECK: Specifies the authorization check level.

Element-Level Annotations

• @Search.defaultSearchElement: true: Marks a field as a searchable element for the freestyle search.
• @Consumption.valueHelpDefinition: [{ entity: { name: 'ENTITY_NAME', element: 'ELEMENT_NAME' } }]: Defines a value help (F4 help) for a field by linking it to a target CDS entity.
• @ObjectModel.text.element: ['FieldName']: Specifies which field contains the textual description for a given ID field (e.g., linking AgencyName to AgencyID).
• @Semantics.amount.currencyCode: 'CurrencyField': Links a numeric amount field to its corresponding currency code field.

Association Redirection

To maintain the RAP hierarchy in a projection, you must redirect composition associations to their respective projection views using the redirected to composition child statement:

_Booking : redirected to composition child ZC_RAP_Booking_####