RE: Action Item 2004-07-01 Solution to 168/R114

 

> -----Original Message-----
> From: Mark Baker [mailto:distobj@acm.org] 
> Sent: 14 July 2004 05:24
> To: Martin Gudgin
> Cc: WS Description List
> Subject: Re: Action Item 2004-07-01 Solution to 168/R114
> 
> On Tue, Jul 13, 2004 at 08:03:05AM -0700, Martin Gudgin wrote:
> > > Nothing but interoperability problems can result from such an 
> > > approach,
> > > IMO.
> > 
> > I don't see any such problems. The WSDL tells you what messages the
> > service accepts and what messages the service emits.
> 
> Exactly.  Information required to understand the semantics of the
> message is in the WSDL, and not in the message; that's the definition
> of non-self-descriptive.  

Err, WSDL doesn't describe the semantics of the messages, does it? Do we
actually HAVE any langauges that can describe the semantics of messages?


> I'm sure I don't need to tell you how
> interoperability is detrimentally affected by a lack of
> self-description.

I don't understand. I, as a service, accept a given set of messages.
When messages that are in that set arrive, I process them and maybe send
other messages. When messages outside the set arrive, I do nothing ( or
generate some kind of fault, perhaps ). I describe in my WSDL what
messages I accept. And what messages I emit. I can recognise which
message is which by inspection. Does that make my messages
self-describing? To who?

> 
> > I'm not pretending there is no operation.
> 
> Sorry, I didn't mean to address that comment to you specifically,
> Gudge; I don't know what you believe in this respect.  But there are
> others here who do believe that.

Actually, I'm with Jim Webber. I think that for some classes of service,
operation is largely illusory, being just a WSDL level construct for
grouping together messages in an exchange. I'm also happy that there are
services for whom there is a strong relationship between the operation
name and some XML element in the input message. I just want to be able
to describe both kinds of services ( and others ) with WSDL.

Gudge

> 
> 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.
>

Received on Wednesday, 14 July 2004 03:15:54 UTC