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Re: fragids and XML style sheets

From: Julian Reschke <julian.reschke@gmx.de>
Date: Fri, 14 Jan 2011 15:03:57 +0100
Message-ID: <4D3057CD.8060807@gmx.de>
To: Jonathan Rees <jar@creativecommons.org>
CC: www-tag@w3.org
On 14.01.2011 14:53, Jonathan Rees wrote:
> I'm not very fluent in the XML stack, so please correct me if I'm
> wrong... but...
> Suppose I retrieve, using a URI U, a 'representation' R1 with media
> type application/xml. Its xml:id attributes define some set of
> fragids, and any fragids not defined by xml:id (or equivalent
> according to DTD or schema??) are defined to be in error. (This is
> what's getting us in trouble with RDFa.) Call this set of fragids F1.
> If the base URI is U, then we have URIs U#id for all id in F1 valid,
> and U#id for id not in F1 erroneous.
> Now suppose that a style sheet transforms the 'representation' into a
> new XML document R2.  That XML document will similarly define a set of
> valid fragids F2.  Again, if the base URI is U, then U#id is valid for
> id in F2, and U#id is erroneous for id not in F2.
> Nothing says that F1 and F2 have to be the same set, and even for ids
> that are in both sets they could easily be defined by R1 and R2 to
> "identify" different elements.

The same problem arises with content negotiation. I'm pretty sure that 
we have a document somewhere that warns about using inconsistent 
fragment identifiers.

> If I'm right - and tell me if I'm not - this adds to our growing list
> of apparent fragid inconsistency threats:
> 1. different interpretations in different representations (conneg,
> session, user-agent, caching, etc.)
> 2. different interpretations from different specs applied to a single
> representation (e.g. xml vs. +xml, or *ml vs. RDFa)
> 3. different interpretations at different pipeline stages (style sheets, GRDDL)
> I wouldn't be surprised if there were more.
> Two questions - first, does this make sense? And second, the TAG had
> some communication with the HTTP WG around #1, which unfortunately I
> can't find right now, either in www-tag email or in the HTTPbis draft.

The only exchange I recall was about the 
recombine-fragids-when-redirect-location-has-a-fragid issue.

That's <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/43>.

> ...

Best regards, Julian
Received on Friday, 14 January 2011 14:04:38 UTC

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