OData – Everything that you need to know (Part 4)
In my previous three blogs, I have covered the basic concepts of HTTP, what are RESTful APIs and their constraints and finally what are Odata service and that they are RESTful services built that uses simple HTTP to communicate between Client and Server.
Previous Blogs in the series:
OData provides a way to expose the data in a uniform way. Although, Microsoft initially came up with the specification of Odata but, there is a lot of industry support behind OData like, Netflix, eBay, IBM. SAP being one of them. In this blog, we will discuss SAP Netweaver Gateway and how along with OData SAP can cater to multiple channels with a unified data model. In future blogs, we will see how to create OData service in a real-world scenario and explain various aspects of OData during the course.
SAP Netweaver Gateway – An Introduction
For Business Users, ease of access has become critical with the advent of various mobile devices that support end-to-end scenarios and also provides a rich user experience. There is a need to better integrate data, reduce complexity and improve productivity. This has been a challenge for the Developer community to be able to support multiple platforms to consume enterprise data more easily than ever before and on the other hand provide solutions that are scalable and with low TCO (Total Cost of Ownership).
Point-to-point solutions are not the right way as it has lot of drawbacks including duplication of development effort, increased cost, complex landscape, poor scalability and difficult to maintain.
SAP Netweaver Gateway is a technology that has the answer to this. It can seamlessly connect devices, platforms and environments to SAP Enterprise Data using the OData services. SAP Netweaver Gateway offers connectivity to SAP Business data using any programming language and without the need of strong SAP development knowledge.
SAP Netweaver Gateway comes with design-time tools to facilitate modeling OData services for consumption. These tools improve user experience and provide automatic connectivity to the SAP backend that reduces development efforts and improves productivity.
SAP Netweaver Gateway sits on top of the existing SAP Backend infrastructure. There are set of add-on components that needs to be installed on a SAP Backend system to enable SAP Netweaver Gateway services. It is this architecture that enables consumption of SAP data by variety of interfaces such as BAPIs and RFCs
SAP Netweaver Gateway Service Builder tools is SAP GUI based modeler to create and publish Odata services using transaction SEGW.
There is also an Eclipse-based Odata Modeler tool available. It provides an easier way to model the service that is a much easier way to develop if you are not too familiar with ABAP programming language. The models can be conveniently created here are exported to the development environment for the Gateway.
SAP Annotation with Odata
SAP has leveraged the extensibility feature provided by Atom Publishing protocol to add SAP specific annotations. AtomPub allows you to add your own markups in the service document. SAP adds annotations from the ABAP Data Dictionary, for example, labels to the documents which can then be consumed by the front end application without having to worry about translations in this case.
In my next blog, I will focus on the various deployment options for SAP Netweaver Gateway.