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Re: Requesting WSDL Files

From: Mark Baker <distobj@acm.org>
Date: Tue, 6 Jul 2004 11:25:44 -0400
To: "Cutler, Roger (RogerCutler)" <RogerCutler@chevrontexaco.com>
Cc: www-ws-arch@w3.org
Message-ID: <20040706152544.GD22429@markbaker.ca>

Hi Roger,

On Tue, Jul 06, 2004 at 09:57:17AM -0500, Cutler, Roger (RogerCutler) wrote:
> Is there anything non-RESTFUL about
> http://example.org/my-web-service?wsdl ?  Looks to me kind of like a lot
> of operations supported by the REST-view of the Web.

It certainly uses a uniform method (GET), which is great.  But as I
tried to describe below, having a convention whereby one needs to
append "?wsdl" to a Web service URI is not RESTful since it doesn't
respect the "hypermedia as the engine of application state" constraint.
AIUI, that constraint basically requires that progression through the
application state machine has to happen via explicit linking, whereas
this convention doesn't do that; the client software has to have
built-in knowledge of that convention in order to get the WSDL data.
For the same reason, it's arguably not even self-descriptive, which is
another of REST's constraints.

What I described below is a more RESTful solution to that problem,
since it makes the relationship between those two resources explicit
in the message.

Mark.

> -----Original Message-----
> From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org] On
> Behalf Of Mark Baker
> Sent: Monday, July 05, 2004 9:45 AM
> To: www-ws-arch@w3.org
> Subject: Re: Requesting WSDL Files
> 
> 
> 
> On Mon, Jul 05, 2004 at 02:33:07PM +0100, Savas Parastatidis wrote:
> > 
> > > 
> > > I just don't see how one could consider WS-RF RESTful .. can you 
> > > expand more please?
> > > 
> > 
> > I agree with Sanjiva. I don't see how WS-RF can be considered as 
> > RESTful. I would say that WS-RF builds an object-oriented or 
> > resource-oriented view of the world using angle brackets but I 
> > wouldn't call that REST. But then again... that's just me :-)
> 
> Yup.
> 
> FWIW, using a URI convention isn't the best way to go about solving the
> WSDL-discovery problem IMO.  A more RESTful solution (i.e. one which
> respects REST's hypermedia-as-engine-of-application-state
> constraint) would be to explicitly declare the relationship between
> service and description, since those are really two resources.  So one
> could imagine doing;
> 
> HEAD http://example.org/my-web-service/ HTTP/1.1
> 
> response;
> 
> HTTP/1.1 200 Ok
> Interface-Description: http://example.org/my-web-service/interface
> 
> which tells us that the returned URI identifies the interface
> description.  Then this request could be used to retrieve the WSDL;
> 
> GET http://example.org/my-web-service/interface HTTP/1.1
> Accept: application/wsdl+xml
> 
> Cheers,
> 
> Mark.
> -- 
> Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca
> 
>   Seeking work on large scale application/data integration projects
>   and/or the enabling infrastructure for same.
> 
> 
> 

-- 
Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca

  Seeking work on large scale application/data integration projects
  and/or the enabling infrastructure for same.
Received on Tuesday, 6 July 2004 11:25:27 GMT

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