22 July 2002 by Ian Davis
Sam Ruby has written an
essay on SOAP + REST in which he proposes four web service world-views: everything is a resource; everything is a get; everything is a message; everything is a procedure. I think he’s missing the point. My understanding of the key difference between the REST and SOAP positions is that resources should be addressable. In REST this means GETting a specific URI to retrieve the representation of, say, the weather forecast for Rome. In SOAP the URI is used as a command target, the command being to retrieve the weather for Rome. The same URI can be resused for retrieving the weather for Moscow and, perhaps, last week’s temperature chart for Athens.
Sam also makes the smart, analogy of SOAP services being the dark matter of the Internet since the lack of a GET interface makes the services inaccessible the majority of Internet clients. His key recommendation here is to maximise the ‘surface area’ of the service by supporting other methods such as GET
Worth reading as another viewpoint on the whole REST vs SOAP debate.