Redefining a Data Service

You can redefine existing data services by using the Redefine Service Wizard. The SAP Gateway Service Builder enables you to make certain restricted changes in the generated services. For example, these services might not have proper labels or might not need all the artifacts. In these cases, the SAP Gateway Service Builder allows you to make cosmetic changes without influencing the underlying implementation of the service.

When generating a service by using redefinition, the data model definition and service implementation are performed in a single step. This is possible because the data sources offer methods that are already very similar to the methods of an OData service.

Two use case can be distinguished:

1. Redefine a data source service.
2. Redefine (or extend) an SAP Gateway service

When redefining a data source, an SAP Gateway service is completely generated based on existing data objects.

For the following frameworks, redefinition scenarios are supported:

Easy Query

Easy Query allows external access to queries created in SAP Business Warehouse (BW).

Multidimensional Expression (MDX)

MDX is a language used in SAP BW and developed by Microsoft for queries using multi-dimensional data. An MDX expression returns a multi-dimensional result set (dataset) that consists of axis data and cell data.

Operational Data Provisioning (ODP)

ODP is an infrastructure for data extraction and replication from SAP (ABAP) applications to a SAP BW/4HANA Data Warehouse.

Business Objects Processing Framework (BOPF)

BOPF is an ABAP object-oriented framework that provides a set of generic services and functionality to speed up, standardize, and modularize development.

Caution

BOPF is also used as business layer in the ABAP Programming Model for SAP Fiori, also known as CDS-based BOPF. In this variant, it cannot be used as data source in a redefinition.

Open Data (OData)

OData services from external systems can be redefined as and thereby transformed in SAP Gateway services.

SAP Gateway (GW)

Redefining an SAP Gateway service allows to extend an (SAP-)delivered one in customer namespace.

Generic Interaction Layer (GenIL)

GenIL is based on the SAP Customer Relationship Management (CRM) Business Object Layer (BOL) and can be used for data access through the GenIL connectivity framework.

Note

The data model is deprecated since ABAP Platform 7.54. The mandatory add-on IW_GIL can no longer be used since SAP S/4HANA 1909.

Service Provider Infrastructure (SPI)

SPI is an application and User Interface (UI) technology independent layer for business data exposure. As application data model, it is used in the SAP Business Suite mainly in the areas Product Lifecycle Management (PLM) and Enterprise Application Management (EAM). As a UI data model, it is used as internal framework for Web Dynpro as part of the Floorplan Manager (FPM).

Note

The usage as application data model is deprecated since AS ABAP 7.51. The mandatory add-on IW_SPI can no longer be used since SAP S/4HANA 1610.

The Redefine Service Wizard looks and works differently for each data model because every data model defines other (runtime) artifacts. Here are some examples:

• BW easy query and MDX are combined in the wizard for BW Query Service and distinguished using the Access Type.
• The OData access for ODP can combine multiple ODPs in one SAP Gateway service.
• A BOPF configuration may include an FPM BOPF Integration (FBI) view.
• The redefinition of an SAP Gateway service asks for a certain version of the original service.

In general, you should be familiar with the data service you want to redefine. Working with the wizard is quite simple as long as the terms and behavior of the origin are understood.

The implementation process starts with redefining a data service. The model and data provider classes are generated depending on the kind of data service chosen. In particular, the generated operations heavily depend on what the data service is providing. After generating the runtime artifacts, the implementation can be tested.

For some data sources, the next step is called beautification. The reason is that OData service are meant to be human readable. But this may not apply to the redefined data source. In fact, the names of fields in the data source may be generated in a very technical manor using character and number chains. Therefore, you literally beautify the data model to make it readable.

As an example, we redefine an SAP Gateway service. You should be familiar with this data source by now. Right-click Data Model and choose Redefine → OData Service (SAP GW). Enter the name and the version of the technical service you want to redefine. If the SAP Gateway service resides in another system, you can fetch the metadata via an RFC destination.

In the second step of the wizard, you select the entity types, properties, and associations you want to be part of your new data model. It is totally fine to only choose parts of the original service if it meets your requirements. Beside the selected elements, a model reference referencing the original model is generated in the new data model.

Depending on the kind of redefined data model, several adaptions are possible. For all data models, it is possible to change the name of entity types, properties, labels, and entity sets. Double-click the element in the data model tree, select the line you want to change, and choose Redefine. Choose Undone to reverse the changes at any time.