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

From: Eric Sedlar <eric.sedlar@oracle.com>
Date: Thu, 16 Oct 2003 21:49:43 -0700
Message-Id: <200310170449.h9H4nqr03312@rgmgw6.us.oracle.com>
To: <dennis.hamilton@acm.org>, "'Julian Reschke'" <julian.reschke@gmx.de>, "'Stanley Guan'" <stanley.guan@oracle.com>, <w3c-dist-auth@w3.org>

The problem is that there is no good way to say:
"ignore any element/attribute you don't understand"
in XML Schema.

--Eric 

> -----Original Message-----
> From: Dennis E. Hamilton [mailto:dennis.hamilton@acm.org]
> Sent: Thursday, October 16, 2003 9:02 PM
> To: Eric Sedlar; Julian Reschke; Stanley Guan; w3c-dist-auth@w3.org
> 
> I don't understand how we got to this point.
> 
> What about this has anything to do with breaking clients?
> 
> I thought the "ignore any element/attribute you don't understand" was a
> pretty clean rule, and trumped the use of extensions *in*the*DAV*XML* by
> another participant in the protocol.  And this goes along with knowing
> that a service may also ignore XML elements and attributes from you that
> it doesn't understand for the level of DAV that it implements.
> 
> The rules to DAV seem pretty clear: new DAV specs that come out can add
> elements to the DAV namespace.   What an older DAV implementation is to do
> with any of that sent its way is well defined.  Any use of a schema
> validator would have to allow for that.
> 
> But I might know that what I am producing (not receiving) is at a
> particular level of DAV, and I use schema assessment to verify that.  And
> if there is an update to DAV, I might have to update the schema I am
> using.  Or not, if I don't intend to use the extension and the rules say
> it is still legal to ignore the extension.
> 
> Where does breaking come in?
> 
> I apologize Eric, I don't know what the context is any more.
> 
> -- Dennis
> 
> 
> -----Original Message-----
> From: Eric Sedlar [mailto:eric.sedlar@oracle.com]
> Sent: Thursday, October 16, 2003 15:34
> To: dennis.hamilton@acm.org; Julian Reschke; Stanley Guan;
> w3c-dist-auth@w3.org
> Subject: Re: DAV Schema Assessment (was Re: rfc2518bis DAV DTD ...)
> 
> 
> Dennis--
> 
>   The issue is not that "anyone can invent an element", but that new DAV
> specs will come out, and would break older clients not updated with the
> new
> schema.  The issue is that XML Schema would constrain the DAV WG's ability
> to extend the specification.
> 
> --Eric
> 
> [ ... ]
> 
Received on Friday, 17 October 2003 00:50:51 GMT

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