savas parastatidis

A WSDL document does not define operation semantics

I had to read this post a number of times to make sure that there wasn’t something I missed since I find myself agreeing with Mark 🙂 (just joking Mark… we’ve agreed before, I think :-).

A WSDL document will not tell you anything about the semantics of an “operation”. WSDL is a contract for the structure of the messages being exchanged. If one wishes to know about the semantics that may be associated with a particular WSDL document, they will have to go to the specification of the service described, find an RDF document for that service, call the service provider on the phone, ask the neighbour. WSDL is not yet another O-O IDL and it certainly does not carry any semantics about the service.

Other related posts: Three posts by Stefan Tilkov (post 1, post 2, post 3) and “WSDL Absolutely Isn’t Yet Another IDL” by Jim (BTW… Mark, Jim’s real blog is on the way).

One response to “A WSDL document does not define operation semantics”

  1. Mark Baker
    Agree? Never!! Then what would I blog about?! 😎 But I never intended to evoke the whole “operation semantics” rathole. I just meant that there needs to be a contract; a way for a requestor to request something be done, and a way for the service to say whether or not it did it, and provide any results of that request. What I hear being discussed doesn’t have that type of contract, yet that type of contract has underlied all successful large scale distributed systems.