Create OData Service in SAP Fiori Server

Overview

• SAP Fiori apps use OData to display and update data in back-end server (SAP or Non-SAP).
• OData (Open Data Protocol) is a standardized protocol for creating and consuming data APIs.
• OData builds on core protocols like HTTP and commonly accepted methodologies like REST.
• Odata supports message formats like JSON, XML.
• OData provides definitions for:
  • Simple Types
  • Complex Types
  • Associations between entries
  • Navigation Paths between entries
  • Custom behavior (known as function imports) beyond the standard QUERY, CREATE, READ, UPDATE, DELETE (QCRUD) operations
• Here we see how to create a Odata-Service which consumes RFC of SAP-R3 (Back-end) server.
• This is a example of business scenario where we need to display/update data of SAP-R3 (Back-end) server in SAP UI5 Application.
• SAP UI5 Applcation consumes Odata-Service which in-turn consumes RFC of SAP-R3.
• This blog is part of below parent blog:
  • SAP Fiori – Custom App Implementation

Steps to create OData service (which consumes RFC):

This is example to consume RFC in OData-Service.

RFC of SAP-R3 (backen-end) Server:

• Functionality of RFC is like, on invoke, it returns MARA table details.
• RFC has one output table structure ‘TBL_MARA‘, in which 10 records will be fetched on execution
• 
• below is RFC code to fetch 10 records from mara table
• 
• This RFC will be consumed in OdataService of SAP-Fiori.

Steps to Create OData Service:

1. Pre-requisites:
   • RFC of SAP-R3 (back-end) system
   • In SAP-Fiori (front-end) system:
     • One RFC-Destination connecting to SAP-R3 (back-end) System
     • T-code    ‘SEGW’
2. Go-to t-code ‘SEGW’ -> click on icon ‘Create Project’
   • 
3. Enter details as shown in screen
   • 
4. Click ‘ok’ icon, OData project gets created
   • 
5. Now we need to create a “Entity-Type” which is meta structure to hold RFC table output
   • Select ‘Entity-Types’ -> right click -. ‘Create’
   • 
   • Enter names as per input.
   • here ‘Entity Type’ is like Data Type and  ‘Entity Set’ is like variable of Data Type.
   • With ‘Entity Set’ name we consume ODataService in UI5 App
   • 
   • Click ‘Ok’ icon
   • 
   • Now, add column (property) in ‘Entity Type’
   • Double Click on Properties -> In center panel click on ‘Append Row’ icon to add new elements
   • 
   • For example purpose, we need only two column details Material Number and its Type, then create two elements
   • And mark ‘Material’ as a key element
   • Now Save and click on icon ‘Generate Runtime Objects’,
   • 
   • Click ok in next pop-up
   • 
   • Enter package details
   • 
   • as a success below screen should appear
   • 
6. Redefine EntitySet method to consume RFC
   • Once Meta structure is been defined, next is to consume RFC
   • For that go to ‘Service Implementation’ -> ‘*_DPC_EXT‘
   • 
   • ‘_DPC_EXT‘ has method ‘_GET_EntitySet‘ which we need to Re-Define, for same we can follow below screen
   • 
   • Once method gets re-defined, we can see it in folder Redefinitions.
   • 
   • Now in ‘_GET_EntitySet’ method we need to do some ABAP Code logic
     • When SAP UI5 Application calls this OdataService with this EntitySet name i.e. ‘MateriallistSet’, GET_ENTITYSET method gets invoked.
     • Here we can write logic to call RFC of SAP-R3 (Back-end) server.
     • RFC returns output in table format, which we need to map structure of OData-Entity-Type ‘Materiallist’
     • Below code can be written for same:

     •   method MATERIALLISTSET_GET_ENTITYSET.
       
       * Structure for RFC's mara table data
         TYPES:
           BEGIN OF ZMARA,
             MATNR TYPE C LENGTH 21,
             MTART TYPE C LENGTH 4,
           END OF ZMARA.
       
         DATA: IT_MARA   TYPE TABLE OF ZMARA,    "internal table to store RFC result
               wA_MARA   TYPE ZMARA,             "work area for single RFC result
               WA_ENTITY TYPE ZCL_ZTEST_ODATA_MPC=>TS_MATERIALLIST.  "work area for Odata Entity 'MaterialList'
       
       * Calling SAR-R3 (Back-Ens) server RFC
         Call FUNCTION 'ZTEST_RFC_FIORI' DESTINATION 'rfcDestinationName'
           TABLES
             TBL_MARA = IT_MARA.
       
       * Return RFC output to Odata Entity output 'MaterialList'
       IF SY-SUBRC = 0.
       *if VALUE FOUND, then map output to Odata Entiy 'MaterialList'
         LOOP AT IT_MARA INTO WA_MARA.
           CLEAR WA_ENTITY.
           WA_ENTITY-MATERIAL  =  WA_MARA-MATNR.
           WA_ENTITY-MTYPE     =  WA_MARA-MTART.
           APPEND WA_ENTITY TO ET_ENTITYSET.   "Append output to Odata Entiy 'MaterialList'
           CLEAR WA_MARA.
         ENDLOOP.
       ENDIF.
         endmethod.
       

     • 
   • Now activate the ‘GET_ENTITYSET‘ method and ‘_DPC_EXT‘.
   • 
7. Thus, a OData Service has been created, which consumes RFC of back-end system.
8. Now next is to register the Service for same, we can follow below link:
   • Register OData Service in SAP Fiori Server
9. Once service gets registered, it can be consumed in SAP UI5 Application for display/upload of back-end data.
10. We can test this ODataService in SAP-Fiori (front-End):
    • t-code              /n/iwfnd/gw_client
    • url                    /sap/opu/odata/sap/ZTEST_ODATA_SRV/MaterialListSet
    • Descritpion      To get RFC detals via EntitySet ‘MaterialListSet’
    • Test screen:
    • 
11. Thus we have developed one OData Service in SAP-Fiori which consumes RFC of SAP-R3.