A simple overview on SAP Netweaver Gateway

SAP 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 SAP NetWeaver Gateway offers connectivity to SAP applications using any programming language or model without the need for SAP knowledge by leveraging REST services and OData/ATOM protocols.

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.

1.3 Key Benefits of SAP NetWeaver Gateway

• REST-enables your SAP system, thereby lowering the data consumption barrier to the point that no specialist knowledge of an SAP system is required before SAP business data and functionality can be consumed.
• Hides the technical complexities of your SAP system landscape behind a single interface that is easy-to-use and non-proprietary.
• Makes your SAP business data and functionality accessible to any external device or system that can:
• Communicate using the HTTP(S) protocol.
• Understand OData messages.
• Provides Service Provisioning tools that allow the quick REST-enablement of existing ABAP functionality.
• Provides plug-ins for well known IDEs such as Eclipse, Visual Studio 2010 and XCode.  

2.0 Accessing SAP Business Data using Open Source tools

Consumption 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 Process

SAP 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.

5.0 Conclusion

SAP 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.