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Re: soap:body and media types (fwd)

From: Mark Baker <distobj@acm.org>
Date: Tue, 31 May 2005 11:36:10 -0400
To: noah_mendelsohn@us.ibm.com
Cc: xml-dist-app@w3.org
Message-ID: <20050531153610.GF3412@markbaker.ca>

Hi Noah,

On Thu, May 19, 2005 at 09:00:38AM -0400, noah_mendelsohn@us.ibm.com wrote:
> Mark Baker writes:
> 
> > I think the disagreement here might be that you
> > seem to be making an assumption which I'm not, and
> > which isn't, AFAICT, licensed by any specification
> > in the stack.  That's not to say that such an
> > assumption can't be used to build successful XML
> > based systems (indeed, it's already in use), only
> > that I think it makes doing so more difficult.
> > 
> > The assumption I'm speaking of sometimes goes by
> > the name "namespace dispatching", and it involves
> > using the namespace of the root element of an XML
> > document to determine the specification by which
> > the contents of the document are interpreted.
> 
> Not quite.  My assumption is that, particularly in the case of 
> meta-formats such as XML, the media type will determine the semantics of 
> the entire family of documents conforming to that media type, and the 
> meaning of any particular document will be determined by its content.

Sounds good...

>In 
> the case of XML, saying that it's application/xml says that interpretation 
> per XML 1.0 is licensed.

Right.

>Beyond that, there may or may not be 
> specifications licensing specific interpretations for particular classes 
> of instance documents.   While I did refer to the common case where such 
> specifications key on a root element, nothing in the argument depends on 
> that. 

Sure.  My argument was similarly independent of where in the document
such an interpretation might be licensed from.  Using the namespace of
the root element just seems to be the most commonly used (and assumed)
mechanism.

> Note that I carefully said in the above legal interpretations of the 
> document, not instructions for processing.  Big difference.

Agreed.  I hope nothing I said suggested otherwise.

Ok, so I'm now wondering where exactly we disagree.  Perhaps its within
the details of your claim above, "there may or may not be specifications
licensing specific interpretations for particular classes of instance
documents"?  Let me test that with an example.

Suppose we have this document;

<Person xmlns="http://personml.example.org/person/">
  <name>Mark Smith</name>
  <age>55</age>
</Person>

as well as a specification called "PersonML" which defines semantics
for describing people using that namespace, and with its own media type,
application/person+xml.

If an author publishes that document as *application/xml* on her Web
server, what information is she conveying to the world?

a) here's some XML which includes, amoungst other things, the character
data "Smith"
b) per the PersonML specification, somebody named Mark Smith is 55 years
old
c) insufficient information to know

If the media type were application/person+xml, what would your answer
be?

FWIW, my answer for the generic media type is c), since RFC 3023 is
ambiguous.  My answer for the specific media type is b).

Do you think that example gets at the issue?

BTW, I'll post a separate response to your other points, since this one
seems to be at the heart of the disagreement.

Cheers,

Mark.
-- 
Mark Baker.  Ottawa, Ontario, CANADA.          http://www.markbaker.ca
Coactus; Web-inspired integration strategies   http://www.coactus.com
Received on Tuesday, 31 May 2005 15:35:42 GMT

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