Gateway Notes (1)

1. Link with OData

OData: developed by Microsoft, is an extension to the Atom Publishing and Atom Syndication standards based on XML & HTTP(S).

More importantly, it is free.

And it is also extensible, which provides the possibility for SAP to build the Gateway based on this idea.

2. Development strategy in Gateway

• (Recommended) IW_BEP installed on business suite backend. And most of the developments take place on backend system.

• Gateway Generator Tool is required for quick prototyping. (Developments on Gateway)
• No add-ons on backend, so most of the custom development took place on Gateway system.
• Gateway within backend. All the stuff will be in one box. (limitation: external access not recommended)

3. Gateway Data Models

Created based on RFM or BOR objects.

Use transaction "/IWFND/GWO_GEN" to map the service and the data model.

4. Consuming Gateway services

Quite flexible because OData is very easy to adapt to. No matter which language just make sure XML is able to be processed.

5. REST and RESTful

REST - Representational State Transfer is Design Concept which defines six architectural constraints.

Any software system (should contain more than 2 entries) that conforms to the constraints of REST, is RESTful.

WWW is the most prominent example of RESTful system.

6. Architectural constraints of REST

1) Client-Server model

2) Layered (client cannot distinguish if the source is the server or proxy)

3) Stateless

4) Uniform

5) Cacheable

6) Code-on-demand (JavaScript is the example)

7. HTTP, a protocol that drives the WWW.

It implements all the mentioned actions that RESTful system should have.