A simple overview on SAP Netweaver GatewaySAP NetWeaver Gateway is a technology that provides a simple way to connect devices, environments and platforms to SAP software based on market standards. The framework enables development of innovative people centric solutions bringing the power of SAP business software into new experiences such as social and collaboration environments, mobile and tablet devices and rich internet applications.

In simple words Netweaver Gateway is a set of ABAP add-ons to your existing SAP ERP system that provides easy access to your business information in a simple, people-centric manner and lowers the data consumption barrier to the point that no prior knowledge of an SAP system's internal workings is required.

The Gateway provides an API that is designed to function as easy–to–use, well defined that gives access to the rich wealth of business data and functionality in your SAP systems.

1.1 The software offers the following capabilities: OPEN - Any Device, Any Experience, Any Platform PEOPLE - Optimized for user interaction scenarios TIMELESS - Non disruptive, any SAP Business Suite version DEVELOPERS - Simple APIs, no SAP knowledge, any tool STANDARDS - Based on REST, ATOM/OData

1.2.1 What is REST & OData?

REST: Representational State Transfer is a style of software architecture for distributed systems such as the World Wide Web. REST has increasingly displaced other design models such as SOAP and WSDL due to its simpler style. REST uses the standard GET, PUT, POST & DELETE methods and other existing features of the HTTP protocol. Key goals of REST include Scalability of component interactions, Generality of interfaces, Independent deployment of components, Intermediary components to reduce latency, enforce security and encapsulate legacy systems.

OData: The Open Data Protocol  is an open web protocol for querying and updating data. The protocol allows for a consumer to query a datasource over the HTTP protocol and get the result back in formats like Atom, JSON or plain XML, including pagination, ordering or filtering of the data.

Open Data Protocol (OData) is a data access protocol initially defined by Microsoft. Versions 1.0,

2.0, and 3.0 are released under the Microsoft Open Specification Promise. Version 4.0 is being

standardized at OASIS,[1] and was released in March 2014.[2]

The protocol was designed to provide standard CRUD access to a data source via a website. It is

similar to JDBC and ODBC although OData is not limited to SQL databases.

OData is built on the AtomPub protocol and JSON where the Atom structure is the envelope that

contains the data returned from each OData request. An OData request uses theREST model for all

requests. Each REST command is a POST, GET, PUT, PATCH, or DELETE http request (mapping

to CRUD) where the specifics of the command are in the URL.

GET: Get a collection of entities (as a feed document) or a single entity(as an entry

document).

POST: Create a new entity from an entry document.

PUT: Update an existing entity with an entry document.

PATCH: Update an existing entity with a partial entry document.

DELETE: Remove an entity.

Any platform that provides support for HTTP and XML is enough to form HTTP requests to interact

with AtomPub. The OData specification defines how AtomPub is used to standardize a typed,

resource-oriented CRUD interface for manipulating data sources.

2.0 Accessing SAP Business Data using Open Source toolsConsumption of data through the SAP NetWeaver Gateway interface requires nothing more than the ability to make an HTTP(S) request. It does not require the use of any SAP proprietary software or protocols. Consumption of data through the SAP NetWeaver Gateway interface does not impose any requirement on the application developer to be able to write software in ABAP, or even to have any understanding of the internal workings of an SAP system.Using the commonly available development tools such as Microsoft’s .Net or Apple’s XCode, or Open Source languages such as Ruby or PHP, we can easily create user interfaces for SAP business data and functionality by consuming the OData messages coming out of an SAP NetWeaver Gateway server. In order to make the OData consumption process even easier, SAP delivers several versions of the Gateway Consumption Tool. This tool can currently be used by either Visual Studio 2010 or XCode and generates an OData proxy object. In addition to this, it can also generate a basic application that wraps the generated proxy object.Microsoft’s OData protocol is based on the Atom Publishing Protocol which in turn, is based on the Atom Syndication Format. SAP has used the standard extensibility features found in OData to provide its own annotations. The combination of OData’s data format and the SAP Annotations make SAP business information both self-describing and human readable. These two factors alone lower the barrier for consuming SAP business data and functionality to the point that no specialist knowledge of an SAP system is required before such data can be incorporated into a useful business application running on some external device.3.0 Focusing area of the SAP NetWeaver Gateway

The whole focus of the SAP NetWeaver Gateway interface is the REST enablement of SAP business data and functionality, thereby making it easy for non-SAP applications to consume. These could be:

Any external business application. E.G. Microsoft Office applications via a .Net (or even VBA) interface

Desktop machines using Web-based applications running PHP or Java or Ruby, etc. Native applications on mobile devices E.G. iPad/iPhone or an Android device or a Blackberry. Embedded devices such as manufacturing robots or route planning software in Satellite

Navigation systems. Any other business scenario you can think of involving some programmable device that can

speak HTTP(S).

The SAP NetWeaver Gateway interface can be used to supply the SAP Business Data to any programmable device that can speak HTTP(S). In providing this capability, it hides the complexities that exist within your system landscape by making use of:

Protocol Adaptation: OData becomes the only communication protocol needed for you to supply or consume SAP Business Data to or from your SAP systems.

Service Adaptation: Different types and versions of SAP systems now appear as a single, integrated repository of business information.

4.0 Development ProcessSAP NetWeaver Gateway software is loaded with various Service Provisioning tools, which generates the necessary source code to jump-start the development of your external business applications. These tools can be used in conjunction with widely used Integrated Development Environments (IDEs) such as Eclipse, Visual Studio 2010 and XCode. Integrated development environment plugins are available for Visual Studio, xCode & Eclipse, so Developers require no SAP Knowledge.SAP NetWeaver Gateway creates new Gateway objects from existing BAPI, RFC & ABAP Dynpro screens. Tools are available like RFC generators, BOR generators and Screen generators which generate new Gateway objects from existing BAPIs, RFCs or Dynpros. We can also build custom Gateway object using Gateway Add-On which provides you with the OData Channel. This is a set of ABAP classes and interfaces that can be used to develop your own Gateway Model Objects within your backend SAP system. These are then registered with your SAP NetWeaver Gateway system in order to make them accessible to the outside world as RESTful services.The steps in development process can be easily understandable from the below image and table. 

 

Step 1 (Gateway) (SAP Side)Step 2 (Consumer IDE) (Eg.

Visual studio, Eclipse)

Pick a Dynpro, a BAPI or existing Gateway Model.Create a Data Source Model through the Gateway Design

Time.Create a simplified Model and the Adaptation Logic in the

Gateway Design Time.

Create Proxy Classes using Plug-ins.

Create a consumer application. 

 

5.0 ConclusionSAP NetWeaver Gateway is not designed to be a channel for the type of transactional applications used by Power Users, neither is it designed to replace existing middleware like SAP NetWeaver PI. In addition to this, SAP NetWeaver Gateway applications are not designed to target A2A or B2B scenarios. Instead, SAP NetWeaver Gateway is the door through which the mass consumption of SAP business data and functionality is made possible. The target audience for SAP NetWeaver Gateway applications is a group known as Occasional Platform Users (OPU). These are people who need ad hoc access to SAP data and functionality in an easy-to-consume manner.