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Re: Synthesis of the proposals for issue 64

From: Jacek Kopecky <jacek@systinet.com>
Date: 18 Jul 2003 13:46:11 +0200
To: Mark Baker <distobj@acm.org>
Cc: WS-Description WG <www-ws-desc@w3.org>
Message-Id: <1058528771.1663.181.camel@localhost>

Mark, 

what I meant (and probably should have said better) was that we don't
need to go out of our way to support describing different web
*resources* in a strongly-typed way. 

On the other hand, specifying an interface with the four HTTP operations
and naming it HTTP in some namespace of ours is a very simple thing to
do and it does not need any changes to the language.

However, I don't think there is a lot of value in actually describing
the HTTP interface as such because it would not really be used much -
either a resource is a part of a greater thing in which case the
interface is more complex and the operations are named differently than
GET, POST etc., or the HTTP resource wants to use WSDL to express some
constraints on the operations, for example the schemas of accepted and
emitted data, and then it will also have a different interface and it's
not really necessary to say on the interface level that it's a
restriction of the HTTP interface. 

I'm presuming that we don't want to add some serious object-oriented
modeling capabilities (operation overriding, for example) to our
interfaces.

Oh, and thanks for the praise there,

                   Jacek Kopecky

                   Senior Architect
                   Systinet Corporation
                   http://www.systinet.com/





On Fri, 2003-07-18 at 04:46, Mark Baker wrote:
> Hi Jacek,
> 
> On Thu, Jul 17, 2003 at 09:47:06AM +0200, Jacek Kopecky wrote:
> > In WSDL, especially in the HTTP binding with URL replacement, we seem to
> > be modeling things that are greater than single HTTP resources. In HTTP
> > services, the model has a bunch of related resources and hypermedia as
> > the state machine, where high-level application operations are performed
> > by various transitions and invoking the HTTP methods. In WSDL, we model
> > the high-level operations and group them into Interfaces.
> 
> That's a brilliant summary, Jacek.
> 
> > Therefore the HTTP application-protocol interface is not really
> > applicable as WSDL interface, as describing a single HTTP resource is
> > less than what WSDL wants to accomplish in one Interface.
> 
> Whoa!  I don't understand that.  By that logic, a stock quote retrieval
> interface isn't applicable as a WSDL interface, because one can always
> develop a stock portfolio management interface which encapsulates it.
> 
> You said it yourself; WSDL describes interfaces, and HTTP defines one.
> I think the conclusion is pretty clear.  And remember, this is all to
> define *extended* functionality for people who want to define RESTful
> services.  My proposal respects the common use of WSDL, and for those
> that aren't defining RESTful services, it's totally business-as-usual;
> they need not ever know that this functionality exists.
> 
> Thanks.
> 
> Mark.
Received on Friday, 18 July 2003 07:46:16 GMT

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