Lesson 21 — Companion: OData, Service Consumption Models and Clean Core

This is your reference while following Lesson 21 — Consuming SAP S/4HANA APIs with OData and Clean Core. Use it when you want to understand what a component does or solve an activation problem. It is not a separate project.

1. The one-sentence purpose of Lesson 21

Read product data stored in SAP S/4HANA from an ABAP application running on SAP BTP, using SAP's supported OData integration tools.

In the preceding HTTP Workshop, you learned to send requests such as GET and inspect JSON. Lesson 21 reuses that understanding and introduces a Service Consumption Model (SCM) that makes an OData response usable as familiar ABAP records.

text

BTP ABAP class
    |
    |  connection from communication arrangement
    v
OData Client Proxy  <--- metadata from Service Consumption Model
    |
    v
S/4HANA OData Product API
    |
    |  remote response
    v
ABAP internal table (generated row structure)

2. The four components most often confused

Component	Beginner explanation	Does it contain live product data?
OData service	A published API for querying and sometimes changing business data	Its responses do
EDMX	The API's machine-readable instruction manual: fields, entities, types	No
Service Consumption Model (SCM)	An ADT repository object generated from the EDMX	No
OData Client Proxy	ABAP runtime API that sends OData requests and maps responses to ABAP	It receives live data when executed

What is an EDMX, exactly?

An EDMX file is XML metadata describing the shape of an OData service. It might define an entity such as A_ClfnProductType with properties Product, ProductType, ProductGroup and BaseUnit.

It is created/published by the API provider (SAP for this S/4HANA API), not by the student consuming it. The $metadata endpoint serves metadata; a Product collection request returns actual product records.

The metadata is imported once when you create or regenerate the SCM. The program then performs real requests when it runs.

Does an SCM automatically establish a connection?

No. The SCM describes the remote API; the communication arrangement provides the outbound connection. The runtime code brings them together.

3. The concrete system we use

Identifier	Purpose
`https://api.sap.com/api/API_CLFN_PRODUCT_SRV/overview`	SAP API documentation and metadata download
`API_CLFN_PRODUCT_SRV`	Remote OData V2 service ID
`ZBTP_TRIAL_SAP_COM_0309`	Shared-Trial outbound communication scenario, where provisioned
`ZSC_L21_PROD_001`	Example locally created SCM / proxy model ID
`ZSC_L21_PROD_001=>TYS_A_CLFN_PRODUCT_TYPE`	Example generated ABAP product row type
`A_CLFN_PRODUCT`	Example generated proxy identifier for the product entity set
`DEFAULT`	Repository ID from the working generated model
`0001`	Example SCM proxy model version; inspect yours

A successful HTTP test was previously observed against the shared S/4HANA Product API in a BTP Trial tenant. That proves this architecture can work, not that every student tenant has the same connectivity or that all shared S/4HANA APIs are exposed.

You do not need the GitHub repository for an SAP workshop to execute this lesson. Everything required is described in the guided content; the SAP Help and API documentation URLs are included there.

4. Find the objects in Eclipse ADT

Open the ABAP perspective

Window → Perspective → Open Perspective → Other… → ABAP.

Open your development package in Project Explorer. If it isn't shown, use Window → Show View → Other… → General → Project Explorer.

Create an ABAP class

Right-click package → New → ABAP Class. Alternative: Right-click package → New → Other ABAP Repository Object… → ABAP Class.

Enter an object name such as ZCL_L21_PRODUCT_PROXY_001, finish the wizard, replace the code, then use Ctrl+S, Ctrl+F3, and F9.

Create a Service Consumption Model

Right-click package → New → Other ABAP Repository Object… → Service Consumption Model.

Choose OData as the Remote Consumption Mode, import API_CLFN_PRODUCT_SRV.edmx, review the generated entities, complete the wizard and activate the SCM.

Find the generated ABAP names

Open the SCM editor → A_ClfnProduct → Read List. Read the sample code to find:

abap

repository_id       = 'DEFAULT'
proxy_model_id      = 'ZSC_L21_PROD_001'
proxy_model_version = '0001'

Look for the generated entity set in create_resource_for_entity_set. Open the generated ABAP class and search for TYS_A_CLFN_PRODUCT_TYPE in its public type declarations. Use your actual names if different.

5. What the ABAP client calls mean

The guided class follows this pattern:

abap

"1. Connection
DATA(lo_destination) =
  cl_http_destination_provider=>create_by_comm_arrangement(
    comm_scenario = 'ZBTP_TRIAL_SAP_COM_0309'
  ).

DATA(lo_http_client) =
  cl_web_http_client_manager=>create_by_http_destination(
    i_destination = lo_destination
  ).

"2. OData model + client proxy
DATA(lo_proxy) =
  /iwbep/cl_cp_factory_remote=>create_v2_remote_proxy(
    is_proxy_model_key = VALUE #(
      repository_id       = 'DEFAULT'
      proxy_model_id      = 'ZSC_L21_PROD_001'
      proxy_model_version = '0001'
    )
    io_http_client = lo_http_client
    iv_relative_service_root = ''
  ).

"3. One collection and a read request
DATA(lo_request) =
  lo_proxy->create_resource_for_entity_set(
    'A_CLFN_PRODUCT'
  )->create_request_for_read( ).

lo_request->set_top( 5 ).

The example above is a fragment, not a standalone class. Use the complete runnable class in the guided lesson for execution.

Why is `iv_relative_service_root = ''` empty?

For this specific shared Trial configuration, the outbound destination already points to the Product OData service root. Adding the full service path a second time would risk an incorrect URL.

Other real landscapes may configure only the host in the destination and therefore require a nonempty relative service root. Do not copy the empty string blindly into unrelated projects; check the destination and the service root used by that project.

Why do we use `create_v2_remote_proxy`?

The imported Product API metadata describes an OData V2 service, so the example uses a V2 client proxy. OData V4 has a different proxy creation method; do not switch to it without changing the service/model.

Why does `get_business_data( )` work?

Your Service Consumption Model provides an ABAP description of the remote entity. The client proxy uses the model to convert the remote OData payload into an internal table whose rows have component fields such as product and product_type.

6. Filtering, paging, and reliable output

An OData collection may contain many products. Do not fetch an unbounded list when you only need a few rows.

Limit the result

abap

lo_request->set_top( 5 ).

Requests at most five rows. It is not a guarantee that five exist. Unless you also request a supported sort order, set_top() does not define which five are returned consistently.

Filter on the server

abap

DATA lt_product_range TYPE if_rap_query_filter=>tt_range_option.
lt_product_range = VALUE #(
  ( sign = 'I' option = 'EQ' low = 'A001' )
).

DATA(lo_filter) =
  lo_request->create_filter_factory( )->create_by_range(
    iv_property_path = 'PRODUCT'
    it_range         = lt_product_range
  ).

lo_request->set_filter( lo_filter ).

This corresponds to the idea of $filter=Product eq 'A001'. The proxy handles constructing and encoding the OData filter from the model.

sign = 'I': include matching values.
option = 'EQ': equality.
low = 'A001': value to match.
iv_property_path = 'PRODUCT': proxy property ID taken from the model.

Empty result is not failure. If lt_products is empty after a successful request, the record may not exist or the filter may exclude everything. An exception/HTTP failure is a separate situation.

Avoid dozens of empty fields

The Product type contains many properties for different categories of products. Service products may not have weights, dimensions or warehouse attributes populated.

Display only what the user needs:

abap

LOOP AT lt_products INTO DATA(ls_product).
  out->write(
    |{ ls_product-product } | &&
    |{ ls_product-product_type } | &&
    |{ ls_product-product_group }|
  ).
ENDLOOP.

7. Understanding Clean Core and released APIs

A company often extends SAP S/4HANA, but future updates become risky when external custom programs depend on private SAP implementation details.

One Clean Core approach is to keep standard code unchanged and integrate via documented, suitable APIs. Here, the Product API is a published interface for product reads. The custom application operates in BTP and requests data through that interface.

C0, C1 and C2 are not OData versions

Contract	Core meaning	Typical usage
C0 — Extend	Defined extension points may be extended	Enhance permitted CDS/RAP behavior
C1 — Use System-Internally	Use a released interface from code in the applicable ABAP system	Local released ABAP API consumption
C2 — Use as Remote API	Published remote interface for external consumers	BTP to SAP back-end integration

Always look at the actual API's release status and documentation. Just because an endpoint responds over HTTP does not mean every field, operation or access path is supported for your production use.

Do not confuse Clean Core with the protocol

A generic REST API and an OData API both communicate over HTTP. Clean Core is about depending on supported interfaces and extension points, not whether you used JSON or typed ABAP data.

8. If live connectivity fails: runnable local fallback

This fallback demonstrates typed ABAP table processing. It is not an SCM test, not a remote call, and must never be reported as S/4HANA connectivity success.

Create the class

Right-click package → New → ABAP Class. Name it ZCL_L21_LOCAL_PRODUCTS_001. Replace the source with this complete example:

abap

CLASS zcl_l21_local_products_001 DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_oo_adt_classrun.
ENDCLASS.

CLASS zcl_l21_local_products_001 IMPLEMENTATION.

  METHOD if_oo_adt_classrun~main.

    "All values are deliberately created locally for this fallback.
    TYPES: BEGIN OF ty_product,
             product       TYPE c LENGTH 40,
             product_type  TYPE c LENGTH 4,
             product_group TYPE c LENGTH 9,
           END OF ty_product.

    DATA lt_products TYPE STANDARD TABLE OF ty_product
      WITH EMPTY KEY.

    lt_products = VALUE #(
      ( product = 'DEMO-001' product_type = 'SERV'
        product_group = 'TRAINING' )
      ( product = 'DEMO-002' product_type = 'SERV'
        product_group = 'TRAINING' )
      ( product = 'DEMO-003' product_type = 'FERT'
        product_group = 'TRAINING' )
    ).

    out->write( 'LOCAL SIMULATION — NOT S/4HANA DATA' ).

    LOOP AT lt_products INTO DATA(ls_product)
      WHERE product_type = 'SERV'.
      out->write(
        |{ ls_product-product } - { ls_product-product_type }|
      ).
    ENDLOOP.

  ENDMETHOD.
ENDCLASS.

Activate using Ctrl+F3 and execute using F9.

Expected result:

text

LOCAL SIMULATION — NOT S/4HANA DATA
DEMO-001 - SERV
DEMO-002 - SERV

Why this helps: It lets you practice structures, tables, WHERE, and output while your tenant's outbound connectivity issue is investigated. You can still import and inspect the EDMX/SCM if those tools work, but this local class does not exercise the OData client proxy.

9. Common problems, clearly explained

Symptom	Likely place to investigate	First action
Cannot find SCM wizard	ADT version, ABAP project, authorization	Use Other ABAP Repository Object search; confirm ABAP perspective
Wizard rejects EDMX	Metadata file/type	Check `.edmx` XML file and correct Product API
Unknown `tys_a_clfn_product_type`	Generated class/type name differs	Open generated class and copy actual type
Unknown `A_CLFN_PRODUCT`	Proxy entity set identifier	Copy identifier from SCM Read List code
`proxy_model_id` / version mismatch	Generated model key	Copy values from SCM sample
Destination not found	Trial scenario access	Confirm `ZBTP_TRIAL_SAP_COM_0309` exists/accessible
HTTP 401 / 403	Authentication/authorization	Inspect configured communication arrangement; do not hard-code secrets
HTTP 404	Wrong service path/root	Inspect destination path and `iv_relative_service_root`
Empty result	Filter/data	Change to known test product and retry
Many empty columns	API returns a broad data model	Print only relevant properties

Reading error messages in ADT

Use Window → Show View → Other… → General → Problems to display activation errors. Double-click one to jump to the source. Runtime errors appear in the ABAP Console or ADT error details and should be recorded without credentials or secret headers.

10. Review questions and answers

Q: Who creates the EDMX?
A: The API provider. Here SAP publishes metadata for the Product OData service.

Q: Does an EDMX contain product A001 and its current attributes?
A: No; it describes the structure and service capabilities. An API read request retrieves records.

Q: Does an SCM open an HTTP connection by itself?
A: No. It is a design-time model. Your ABAP code creates a client and executes a request through the configured destination.

Q: Why did direct HTTP return JSON, while the proxy returned a typed ABAP table?
A: The proxy uses metadata from the SCM to map OData responses into generated ABAP types.

Q: Do we always use iv_relative_service_root = ''?
A: No. It is correct for the specific shared Trial destination shown in the guided example. Other destinations may not already point to the service root.

Q: Is OData the same thing as RAP?
A: No. OData is a standard API protocol. RAP is an ABAP development model that can expose and consume services in broader application scenarios.

Q: Are product IDs always A001–B003?
A: No. Those values came from one working demonstration response. A different remote dataset may return different products.

Q: Why not use the JSONPlaceholder service from the HTTP Workshop?
A: It's useful to learn generic REST/HTTP, but it does not supply the OData metadata/service model needed for this SCM exercise.

Q: How will this help later?
A: The next side-by-side integration project can use a remote Product API as a value help or data source for a custom RAP/Fiori application.

11. Reference URLs

SAP Product API documentation and EDMX: https://api.sap.com/api/API_CLFN_PRODUCT_SRV/overview
SAP Developer — Outbound OData Call via SCM: https://developers.sap.com/tutorials/abap-environment-business-partner-outbound-call
SAP Help — Prepare Access to Remote OData: https://help.sap.com/docs/abap-cloud/abap-rap/preparing-access-to-remote-odata-service
SAP Help — Create a Remote Client Proxy: https://help.sap.com/docs/abap-cloud/abap-rap/creating-remote-client-proxy
SAP Help — OData Client Proxy User Guide: https://help.sap.com/docs/abap-cloud/abap-integration-connectivity/odata-client-proxy-user-guide
SAP Help — HTTP Outbound Service and Default Path Prefix: https://help.sap.com/docs/abap-cloud/abap-integration-connectivity/outbound-service

Code verification note: The main proxy class in the guided lesson uses the same model and type patterns that already ran successfully in a BTP Trial tenant. The filtered example and this companion's offline fallback have been reviewed as source, but not activated in your tenant during this file creation.

Lesson 21 — Companion: OData, Service Consumption Models and Clean Core ​

1. The one-sentence purpose of Lesson 21 ​

2. The four components most often confused ​

What is an EDMX, exactly? ​

Does an SCM automatically establish a connection? ​

3. The concrete system we use ​

4. Find the objects in Eclipse ADT ​

Open the ABAP perspective ​

Create an ABAP class ​

Create a Service Consumption Model ​

Find the generated ABAP names ​

5. What the ABAP client calls mean ​

Why is iv_relative_service_root = '' empty? ​

Why do we use create_v2_remote_proxy? ​

Why does get_business_data( ) work? ​

6. Filtering, paging, and reliable output ​

Limit the result ​

Filter on the server ​

Avoid dozens of empty fields ​

7. Understanding Clean Core and released APIs ​

C0, C1 and C2 are not OData versions ​

Do not confuse Clean Core with the protocol ​

8. If live connectivity fails: runnable local fallback ​

Create the class ​

9. Common problems, clearly explained ​

Reading error messages in ADT ​

10. Review questions and answers ​

11. Reference URLs ​

Lesson 21 — Companion: OData, Service Consumption Models and Clean Core

1. The one-sentence purpose of Lesson 21

2. The four components most often confused

What is an EDMX, exactly?

Does an SCM automatically establish a connection?

3. The concrete system we use

4. Find the objects in Eclipse ADT

Open the ABAP perspective

Create an ABAP class

Create a Service Consumption Model

Find the generated ABAP names

5. What the ABAP client calls mean

Why is `iv_relative_service_root = ''` empty?

Why do we use `create_v2_remote_proxy`?

Why does `get_business_data( )` work?

6. Filtering, paging, and reliable output

Limit the result

Filter on the server

Avoid dozens of empty fields

7. Understanding Clean Core and released APIs

C0, C1 and C2 are not OData versions

Do not confuse Clean Core with the protocol

8. If live connectivity fails: runnable local fallback

Create the class

9. Common problems, clearly explained

Reading error messages in ADT

10. Review questions and answers

11. Reference URLs