SOAP? REST? Whichever you choose, WCF is the right framework
November 14, 2007
Sidenote: speaking of multiple interfaces for the same resource, check out what Amazon did with SQS: there is a REST interface, a SOAP interface (described in WSDL) and a QUERY interface. The REST interface is bona-fide REST. It uses HTTP verbs like (GET DELETE PUT POST), and the URI corresponds or maps to the resource in question, for example the queue you’d like to operate on. In WCF, to build this sort of interface, you would use a [WebInvoke] attribute on your service interface. The QUERY interface on the Amazon SQS resource is, like the REST interface, always based on HJTTP, but QUERY is different than REST in that QUERY is always an HTTP GET, and specifies the object and verb in the URI.
Example:
The QUERY request to create a queue:
GET /?Action=CreateQueue&QueueName=Foo HTTP/1.1
Host: queue.amazonaws.com
The REST request to create a queue:
POST /?QueueName=Foo HTTP/1.1
Host: queue.amazonaws.com
Some people confuse or conflate REST with HTTP QUERY, but Amazon certainly does not. It doesn’t help matters that there is no widely accepted or adopted name for the HTTP QUERY services interface. Amazon calls it HTTP QUERY or justr QUERY but as far as I am aware, that name is not widely used by other systems who expose similarly architected interfaces.
How about “Abomination”? ;-)
About
This page contains a single entry from Stefan Tilkov's Random Stuff posted on November 14, 2007 11:31 AM. The previous post in this blog was WS-* and CORBA. The next post in this blog is WS-* is to REST as Theory is to Practice. Many more can be found on the main index page or by looking through the archives.
Comments
I like The Book’s name for these: “REST/RPC hybrid.”
Posted by: Aristotle Pagaltzis at November 14, 2007 4:13 PM | link
Stefan,
The use of an overloaded GET to cover all verbs should be called HTTP Command. It’s the Command pattern over HTTP.
Actually, I think if they restrict the use of this pattern to just the three idempotent verbs (GET, PUT and DELETE) and use the POST-Redirect-GET pattern with POSTS, it wouldn’t be a bad substitute for a purely RESTful system. It would just lack formality.
Ganesh
Posted by: Ganesh Prasad at November 19, 2007 3:28 PM | link
Ganesh, it would not only lack formality, it would still be quite disastrous if GET’s safety guarantee was violated.
Posted by: Stefan Tilkov at November 21, 2007 11:11 AM | link