Redefining the Expand Methods of the Extension DPC

If all entity sets of a Gateway service are mapped to Business Entities and the restriction of the optimized SADL $expand can be accepted by the application, as discussed in the previous chapter, the optimized SADL $expand can be used.

Prerequisites

This feature is available since SAP NetWeaver 7.4 SP10.

Context

If some of the entity sets in your OData service are not mapped to a business entity, see how you can support navigation in a hybrid scenario in combination with the optimized expand in the next section.

To optimize $expand, follow these steps:

Procedure

  1. Redefine the get_expanded_entity and get_expanded_entityset methods in the generated *_dpc_ext class of your service: 
      PUBLIC SECTION.
     METHODS /iwbep/if_mgw_appl_srv_runtime~get_expanded_entity REDEFINITION.
     METHODS /iwbep/if_mgw_appl_srv_runtime~get_expanded_entityset REDEFINITION.
  2. Implement the get_expanded_entity method. 
      METHOD /iwbep/if_mgw_appl_srv_runtime~get_expanded_entity.
    " -------------------------------------------------
    " ...
    " Implement application specific logic of get_entity methods here (if any)
    " ...
    " -------------------------------------------------
    " Read entity data (and expand):
    if_sadl_gw_dpc_util~get_dpc( )->get_expanded_entity( 
        EXPORTING io_expand_node           = io_expand
                  io_tech_request_context  = io_tech_request_context
        IMPORTING er_entity                = er_entity
                  et_expanded_tech_clauses = et_expanded_tech_clauses
                  es_response_context      = es_response_context ).
  ENDMETHOD.
  3. Implement the get_expanded_entityset method. 
      METHOD /iwbep/if_mgw_appl_srv_runtime~get_expanded_entityset.
    " -------------------------------------------------
    " ...
    " Implement application specific logic of get_entityset methods here (if any)
    " ...
    " -------------------------------------------------
    " Read entity data (and expand):
    if_sadl_gw_dpc_util~get_dpc( )->get_expanded_entityset( 
           EXPORTING io_expand_node           = io_expand
                     io_tech_request_context  = io_tech_request_context
           IMPORTING er_entityset             = er_entityset
                     et_expanded_tech_clauses = et_expanded_tech_clauses
                     es_response_context      = es_response_context ).
  ENDMETHOD.