- From: Jo Rabin <jrabin@mtld.mobi>
- Date: Mon, 22 Jun 2009 17:37:48 +0100
- To: "Francois Daoust" <fd@w3.org>, "Mobile Web Best Practices Working Group WG" <public-bpwg@w3.org>
"Oh no!", the lemming says ... > [[ > the content is HTML and contains <link rel="alternate" > media="handheld" href="[same-ref]"/> where [same-ref] is a "Same > Document reference" as defined in RFC 3986 section 4.4 [REF]. In > particular, an empty href attribute is a "Same Document Reference". > ]] But this won't work for a multi-serving environment, will it. We are left with only using a vary header in such situations? Jo > -----Original Message----- > From: public-bpwg-request@w3.org [mailto:public-bpwg-request@w3.org] On > Behalf Of Francois Daoust > Sent: 22 June 2009 16:43 > To: Mobile Web Best Practices Working Group WG > Subject: ACTION-983: same-document reference > > Hi, > > Discussion on "same-document" references started a long time ago when > Dom managed to have the group follow his unwise principle that a URI > always represents the resource and not a given representation of the > resource. This led to the production of a very smart algorithm in the > last call version of the guidelines. This was shortly followed by last > call comment LC-2009 [1]. The comment pointed us to section 4.4 of > RFC3986 "Uniform Resource Identifier (URI): Generic Syntax" [2] that > defines the concept of "same-document reference". > > In particular, it does say: > [[ > When a same-document reference is dereferenced for a retrieval > action, the target of that reference is defined to be within the > same > entity (representation, document, or message) as the reference; > therefore, a dereference should not result in a new retrieval > action. > ]] > ... meaning that a URI that appears in the representation of a resource > and that happens to be a same-document reference represents the > representation of the resource, and not the resource itself. > > We blamed Dom. We still had extensive discussions on the topic such as > in [3], in particular because it also connects with the ("Oh no!", the > Lemming says and explodes) ISSUE-222 [4] and the TAG Finding On Linking > Alternative Representations To Enable Discovery And Publishing [5]. The > thing is the theory does not entirely match practice and most (all?) > browsers do not correctly handle the case when you want to use a > canonical URI for bookmarking purpose. Plus there is no true way to > define a URI as the canonical URI for a set of representations [6]. > > Whilst this is true, it is not directly related to the definition of a > "same-document reference" and does not change its definition either. In > short, unless we have good reasons not to, we should stick to the > definition of the above-mentioned RFC, and this is exactly what > Appendix > G.1.4.2 [7] does. > > However, the first bullet point in section 4.2.9 [8] restricts the > possibility of a "Same Document reference" to an empty href attribute. > For consistency, the text should rather be: > [[ > the content is HTML and contains <link rel="alternate" > media="handheld" href="[same-ref]"/> where [same-ref] is a "Same > Document reference" as defined in RFC 3986 section 4.4 [REF]. In > particular, an empty href attribute is a "Same Document Reference". > ]] > > Francois. > > > [1] > http://www.w3.org/2006/02/lc-comments-tracker/37584/WD-ct-guidelines- > 20080801/2009 > [2] http://tools.ietf.org/html/rfc3986.html#section-4.4 > [3] http://lists.w3.org/Archives/Public/public-bpwg- > ct/2008Sep/0027.html > [4] http://www.w3.org/2005/MWI/BPWG/Group/track/issues/222 > [5] http://www.w3.org/2001/tag/doc/alternatives-discovery.html > [6] http://lists.w3.org/Archives/Public/public-bpwg/2009Feb/0096.html > [7] > http://www.w3.org/2005/MWI/BPWG/Group/TaskForces/CT/editors- > drafts/Guidelines/090622#sec-use-of-link-element > [8] > http://www.w3.org/2005/MWI/BPWG/Group/TaskForces/CT/editors- > drafts/Guidelines/090622#sec-proxy-decision-to-transform
Received on Monday, 22 June 2009 16:38:31 UTC