Here's an article on the topic: "Code-Based Implementation of OData Services in SAP Gateway", suitable for the subject SAP-Gateway within the SAP field.
SAP Gateway enables seamless integration between SAP systems and external clients through OData (Open Data Protocol) services. While SAP provides tools like Service Builder (Transaction Code SEGW) for a model-driven development approach, many advanced use cases require a more flexible and powerful technique: code-based implementation.
This article explains the concept, advantages, and step-by-step process of code-based OData service development in SAP Gateway.
Code-based implementation refers to manually creating the components of an OData service—such as the data model, runtime classes, and service registration—without using the graphical SEGW tool. It gives developers full control over service behavior and is particularly useful when:
DPC)MPC)Create a Custom Class for MPC:
/IWBEP/CL_MGW_ABS_MODELDEFINE to define entity types and sets using ABAP codeMETHOD define.
DATA: lo_entity_type TYPE REF TO /iwbep/if_mgw_odata_entity_typ,
lo_entity_set TYPE REF TO /iwbep/if_mgw_odata_entity_set.
lo_entity_type = model->create_entity_type( 'Product' ).
lo_entity_type->create_property( iv_property_name = 'ID' iv_abap_fieldname = 'ID' ).
lo_entity_type->create_property( iv_property_name = 'Name' iv_abap_fieldname = 'NAME' ).
lo_entity_set = model->create_entity_set( 'Products', 'Product' ).
ENDMETHOD.
Create a Custom Class for DPC:
/IWBEP/CL_MGW_ABS_DATAGET_ENTITY, GET_ENTITYSET, CREATE_ENTITY, etc.METHOD products_get_entityset.
DATA: lt_entityset TYPE STANDARD TABLE OF zproduct,
ls_entity TYPE zproduct.
SELECT * FROM zproduct INTO TABLE lt_entityset.
LOOP AT lt_entityset INTO ls_entity.
APPEND VALUE #( id = ls_entity-id name = ls_entity-name ) TO et_entityset.
ENDLOOP.
ENDMETHOD.
/IWFND/MAINT_SERVICE to register the service.Once registered, you can test the service using:
/IWFND/GW_CLIENT)Examples:
GET /sap/opu/odata/SAP/ZPRODUCT_SRV/ProductsGET /sap/opu/odata/SAP/ZPRODUCT_SRV/$metadata| Feature | Advantage |
|---|---|
| Flexibility | Full control over implementation |
| Performance | Optimized for complex data models |
| Custom Logic | Easily include validation, logging, or business rules |
| No SEGW Dependency | Lightweight and manageable for small teams |
| Use Case | Recommendation |
|---|---|
| Simple CRUD operations | Use SEGW (model-based) |
| Complex logic or reusing legacy code | Use code-based implementation |
| Fine-tuned performance requirements | Prefer code-based |
Code-based implementation of OData services in SAP Gateway is a powerful technique that complements the SEGW model-based approach. It is ideal for scenarios demanding custom logic, performance optimization, and integration with complex backend systems. While it requires a deeper understanding of OData protocols and ABAP programming, the flexibility and control it provides are well worth the effort.