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RE: DAV Schema Assessment (was Re: rfc2518bis DAV DTD ...)

From: Dennis E. Hamilton <dennis.hamilton@acm.org>
Date: Thu, 16 Oct 2003 13:02:06 -0700
To: "Julian Reschke" <julian.reschke@gmx.de>, "Stanley Guan" <stanley.guan@oracle.com>, <w3c-dist-auth@w3.org>
Message-ID: <FFEPLLNFAHGBKNENFGPAKEHNDDAA.dennis.hamilton@acm.org>

Julian,

With regard to schema-definition maintenance, I was referring only to extension to the DAV: namespace, not the occurrence of ad hoc elements from other namespaces.  

With regard to schema assessment, I believe XML Schema has ways to allow for occurrence of elements that are from namespaces other than the one covered by a particular schema definition, if you can delimit where such occurrences are allowed.  (I have not checked this as carefully as Stanley may have, however, and the response from Henry Thompson is not clear to me on that point.  I was relying on Stanley's illustration and I did not go check the XML Namespace specs myself, nor review how lax assessment is specified.)  

I think I understand both how the DAV namespace is extensible (by agreement) and how DAV XML elements are extensible (by ad hoc additions having nothing to do with the DAV namespace).

The only case that a reference XML schema definition for DAV would need to be maintained is with regard to the first part.  The second case is up to the people who define/use ad hoc additions. [Because there is no 100%, I see no reason to settle for 0%.  It's not a binary question for me.]

Does that fit your understanding of DAV extensibility?  

If you're telling me that anyone can invent an element and DAV-validly introduce it as if under the DAV namespace, I will quietly pick up my marbles and go figure out how to use SOAP (with attachments) and the Web Services stack on HTTP to do Document Authoring and Versioning on the web. (Such an expression of some level of DAV functionality is probably valuable anyway.) 

-- Dennis

-----Original Message-----
From: Julian Reschke [mailto:julian.reschke@gmx.de]
Sent: Thursday, October 16, 2003 00:32
To: dennis.hamilton@acm.org; Stanley Guan; Julian Reschke;
w3c-dist-auth@w3.org
Subject: RE: DAV Schema Assessment (was Re: rfc2518bis DAV DTD ...)


Dennis,

I think you're still missing a basic fact about WebDAV's extensibility: it
is not centralized, nor linear. There is no common registry. Everybody can
add extension elements anytime. Even if somebody would update that Schema
anytime a new RFC (or Internet Draft) comes out out, there will be a lot of
legal WebDAV messages that won't validate against that schema.

Julian

--
Received on Thursday, 16 October 2003 16:02:13 GMT

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