RE: On WSDL "operation"

Mark:

> I don't think "objects" is implied, but invokable interfaces, 
> sure, 'cause that what all this SOA stuff is about, no?

No. Services are entites which exchange messages, period. Web Services are
characterised by the exchange of structured documents described with XML
Schema (normally). WSDL is a means of describing those documents and how
they will be exchanged between a single client/requester/consumer (or insert
today's WSA term here) and a service (similarly, insert today's WSA term
here).

> Otherwise you're just talking bit transport.

Nope. I am constraining that much further than just saying that we send bits
around. I am saying that services deal with receving and sending documents.

> What's important from a WSDL POV is the application 
> semantics; what does it *mean* for those bits to get there, 
> and what does the sender of those bits know if a successful 
> response is returned, for example.

That's application level. At the WSDL level there are no such semantics.
WSDL doesn't know about applications, WSDL knows about messages. What the
application does with that message is out-of-scope for WSDL. If you want to
describe the semantics of the message exchange, then pull in some semantic
description language stuff into your Web Service description. It might be a
really useful addition to the message-level stuff that WSDL deals with.

Jim

Received on Tuesday, 16 September 2003 11:48:50 UTC