Getting Started with ABAP Cloud & SAP RESTful Application Programming Model (RAP)

ABAP Cloud is the modern development model for SAP S/4HANA and SAP BTP ABAP Environment. At its heart lies the **RESTful Application Programming Model (RAP)**, designed to build transactional, cloud-native OData services seamlessly.

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//1. Introduction to ABAP Cloud

With SAP S/4HANA, traditional ABAP programming patterns (such as direct database modifications via `MODIFY ztable` inside SAPGUI screens) are superseded by strict released APIs and business object frameworks.

Key tenets of ABAP Cloud: - **Clean Core Strategy**: No direct modifications to standard SAP objects. - **Strict ABAP Syntax**: Cloud-enabled ABAP rules with restricted language scope. - **CDS-first Data Modeling**: Core Data Services drive entity relationships.

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//2. RAP Architecture Overview

RAP segregates applications into distinct architectural layers: 1. **Data Model Layer**: CDS Data Definitions (Root View Entities & Projection Views). 2. **Behavior Layer**: Behavior Definitions (`BDEF`) and Behavior Implementations (`ABAP Class`). 3. **Service Layer**: Service Definition (`SRVD`) and Service Binding (`SRVB`).

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//3. Creating Data Model (CDS View)

Define your root view entity for a Sales Order header:

abap

1@AccessControl.authorizationCheck: #NOT_REQUIRED

2@EndUserText.label: 'Sales Order Header View'

3define root view entity ZR_SalesOrderTP

4 as select from zso_header

5 composition [0..*] of ZR_SalesOrderItemTP as _Item

7 key order_uuid as OrderUUID,

8 order_id as OrderID,

9 customer_id as CustomerID,

10 order_status as OrderStatus,

11 total_amount as TotalAmount,

12 currency_code as CurrencyCode,

14 /* Associations */

15 _Item

16}

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//4. Behavior Definition (BDEF)

Specify standard CRUD capabilities (`create`, `update`, `delete`) and custom actions:

abap

1managed implementation in class zbp_r_salesordertp unique;

2strict ( 2 );

4define behavior for ZR_SalesOrderTP alias SalesOrder

5persistent table zso_header

6lock master

7authorization master ( instance )

9 create;

10 update;

11 delete;

13 field ( readonly, numbering : managed ) OrderUUID;

14 field ( readonly ) OrderStatus;

16 action ( features : instance ) approveOrder result [1] $self;

18 mapping for zso_header

19 {

20 OrderUUID = order_uuid;

21 OrderID = order_id;

22 CustomerID = customer_id;

23 OrderStatus = order_status;

24 TotalAmount = total_amount;

25 CurrencyCode = currency_code;

26 }

27}

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//5. Behavior Implementation (ABAP Class)

Implement the custom `approveOrder` action using EML (Entity Manipulation Language):

abap

1CLASS lhc_SalesOrder DEFINITION INHERITING FROM cl_abap_behavior_handler.

2 PRIVATE SECTION.

3 METHODS approveOrder FOR MODIFY

4 IMPORTING keys FOR ACTION SalesOrder~approveOrder RESULT result.

5ENDCLASS.

7CLASS lhc_SalesOrder IMPLEMENTATION.

8 METHOD approveOrder.

9 " Modify entity status via EML

10 MODIFY ENTITIES OF ZR_SalesOrderTP IN LOCAL MODE

11 ENTITY SalesOrder

12 UPDATE FIELDS ( OrderStatus )

13 WITH VALUE #( FOR key IN keys ( OrderUUID = key-OrderUUID

14 OrderStatus = 'APPROVED' ) )

15 FAILED failed

16 REPORTED reported.

18 " Read updated values for action result

19 READ ENTITIES OF ZR_SalesOrderTP IN LOCAL MODE

20 ENTITY SalesOrder

21 ALL FIELDS WITH CORRESPONDING #( keys )

22 RESULT DATA(lt_orders).

24 result = VALUE #( FOR order IN lt_orders ( %tky = order-%tky %param = order ) ).

25 ENDMETHOD.

26ENDCLASS.

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//6. Preview & Testing in Fiori Elements

Publish a **Service Definition** and generate a **Service Binding (OData V4)**. ADT (ABAP Development Tools in Eclipse) provides an integrated SAP Fiori Elements Preview tool to interactively test your full-stack application!

Getting Started with ABAP Cloud & SAP RESTful Application Programming Model (RAP)

Getting Started with ABAP Cloud & SAP RESTful Application Programming Model (RAP)

//1. Introduction to ABAP Cloud

//2. RAP Architecture Overview

//3. Creating Data Model (CDS View)

//4. Behavior Definition (BDEF)

//5. Behavior Implementation (ABAP Class)

//6. Preview & Testing in Fiori Elements

K Sai Bhaskar

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