- From: Steven Pemberton <steven.pemberton@cwi.nl>
- Date: Wed, 01 Feb 2006 13:16:46 +0100
- To: Ben Adida <ben@mit.edu>
- Cc: Jeremy Carroll <jjc@hpl.hp.com>, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "Miles, AJ (Alistair)" <A.J.Miles@rl.ac.uk>, SWBPD list <public-swbp-wg@w3.org>, public-rdf-in-xhtml task force <public-rdf-in-xhtml-tf@w3.org>, Pat Hayes <phayes@ihmc.us>
Ben Adida wrote: > Continuing on this point, I guess that implies the following thing: > > If http://example.com/foo resolves to an XHTML document, then > http://example.com/foo#bar can only be an information resource. However, > if http://example.com/foo resolves to an N3 document, then > http://example.com/foo#bar *can* be an information resource, because > there is no way to get a fragment of an N3 document. > > The first consequence is that XHTML documents are somehow second-class > citizens to N3 in expressing semweb statements. That would be truly > unfortunate. > > The second consequence is that the RDF type of a frag URI now depends on > the Mime Type of the non-frag URI. That seems bad, too. Following on from what I believe Mark was saying at the last call, http://example.com/foo may resolve to both an XHTML document *and* an N3 document (and many other things) depending on the accept: headers, so http://example.com/foo#bar could represent (many) different things. Steven > > -Ben > > On Jan 31, 2006, at 12:50 PM, Jeremy Carroll wrote: > >> >> It is of course conceivable that we are identifying a bug with the web >> architecture document rather than a bug in our use of URIs. >> >> The space of URIs available for non-Information resources seems to be >> getting smaller and smaller, soon the Semantic Web will be disallowed >> by the Web Architecture document. >> >> Jeremy >> >> Booth, David (HP Software - Boston) wrote: >>>> From: Miles, AJ (Alistair) [mailto:A.J.Miles@rl.ac.uk] >>>> I think that, because no element with the id attribute value "me" is >>>> actually present in the document, then current specifications [3,4] >>>> do not allow any conclusions about the nature of <#me> to be drawn >>>> from the content-type of the document. >>> I don't think that's quite correct. The WebArch makes no requirement >>> that the fragment identifier actually exist in the retrieved document. >>> The dependency is on whether a *representation* exists when the primary >>> resource is dereferenced. From WebArch sec 3.2.1: >>> [[ >>> The semantics of a fragment identifier are defined by the set of >>> representations that might result from a retrieval action on the primary >>> resource. The fragment's format and resolution are therefore dependent >>> on the type of a potentially retrieved representation, even though such >>> a retrieval is only performed if the URI is dereferenced. If no such >>> representation exists, then the semantics of the fragment are considered >>> unknown and, effectively, unconstrained. >>> ]] >>> Thus, my interpretation of the WebArch is that if http://example.org/foo >>> returns application/xhtml+xml, then RFC3236 applies, which states: >>> ". . . fragment identifiers for XHTML documents designate the >>> element with the corresponding ID attribute value". If no such >>> element exists, then http://example.org/foo#me identifies a >>> non-existent element. The fact that no such element actually exists >>> does not change the fact that that is what the URI identifies. >>>> . . . >>>> Please note my position given at [7]: 'I support publication of this >>>> document as a Working Draft'. I do not think the publication of >>>> RDF/A as Working Draft should be delayed because of this particular >>>> discussion thread. >>> I agree. I think the warning that Ben has added is adequate. >>> David Booth >>>> [3] http://www.w3.org/TR/2004/REC-webarch-20041215/#media-type-fragid >>>> [4] http://www.ietf.org/rfc/rfc3236.txt >>>> [5] >>>> http://lists.w3.org/Archives/Public/public-swbp-wg/2006Jan/0152.html >>>> [6] >>>> http://lists.w3.org/Archives/Public/public-swbp-wg/2006Jan/0153.html >>>> [7] >>>> http://lists.w3.org/Archives/Public/public-swbp-wg/2006Jan/0113.html >> >> >> > >
Received on Wednesday, 1 February 2006 12:17:01 UTC