- From: Julian Reschke <julian.reschke@gmx.de>
- Date: Fri, 14 Jan 2011 15:03:57 +0100
- 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