- From: Ben Adida <ben@adida.net>
- Date: Fri, 31 Aug 2007 15:25:29 -0700
- To: Mark Birbeck <mark.birbeck@formsPlayer.com>
- CC: Karl Dubost <karl@w3.org>, RDFa <public-rdf-in-xhtml-tf@w3.org>
I concur with Mark that priorities are prone to too much complexity: if there are duplicate triples, then there are duplicate triples, it's not the end of the world and it wouldn't be the first time :) I'm loathe to start interpreting XHTML as RDFa in most cases, but I can see the reason for <title>. That said, I don't see how we can make the executive decision, in this task force, to map to dc:title. At best, xh:title, as Mark mentions. Oh and one more thing about Karl's markup: those should be plain literals, not XMLLiterals. Our decision a few months ago was that if there is no markup within the content, then it is a plain literal. -Ben Mark Birbeck wrote: > Hi Karl, > > I don't recall this being discussed in the task force, so it would be > interesting to hear other views. However, it *was* discussed in the > XHTML 2 Working Group when we first started to work on RDFa, and we > concluded: > > * that you can't really have priorities for the triples, since that > makes parsing very complex. Any > 'priorities' or overlaid meanings need to come from an > interpretation of the derived triples, and > not by trying to understand the triples in the parsing stage; > > * as with your comment, we also thought that <title> should express dc:title. > > The h:title => dc:title part is a little controversial, and in > particular it does favour one taxonomy over others. As a consequence > it hasn't been introduced into the XHTML+RDFa 'dialect' that is being > worked on in the task-force. However, seeing your examples, I'm now > wondering whether having this 'shorthand' for dc:title is a good idea > at all! > > What we could do instead is to say that, yes, <title> is a shorthand, > but that it generates a predicate in the XHTML namespace, rather than > Dublin Core's: > > <> xh:title "The Old Man And The Sea - Literature" . > > (Note that if there is no mark-up in the element content, we don't > default to XML literals.) > > With this triple it would be a simple matter to establish precedence > when presented with the following triples from your example: > > <> dc:title "The Old Man And The Sea, Ernest Hemingway" . > <> dc:title "The Old Man And The Sea, Hemingway" . > <> xh:title "The Old Man And The Sea - Literature" . > > The key point is that the precedence is worked out at the level of the > generated triples, and not whilst in the process of parsing the > initial mark-up, which is bound to be better. > > Note by the way that strictly speaking the <title> is the title of the > information resource sitting at the current URL, and therefore can't > be the title of a book. So in reality this problem of 'priority' > arises in situations like news stories, where the article title is in > the first <h1> as well as in <title>. The odd thing here though is > that you might actually want <h1> to take precedence. > > The situation that would seem to be the most common would be something > like the following, from today's Times: > > <html> > <head> > <title> > Empty seats at service show scars of Diana’s life have > not all healed > </title> > </head> > <body> > <h1 class="heading"> > Empty seats at service show scars of Diana’s life have > not all healed > </h1> > ... > </body> > </html> > > Reading @class="heading" as @property="dc:title", we see that the two > titles are exactly the same. > > However, The Sun, has the story like this: > > <html> > <head> > <title> > The Sun Online - Royals: Diana tribute gets underway > </title> > </head> > <body> > <h1 class="black32"> > Diana tribute gets underway > </h1> > ... > </body> > </html> > > It's quite a reasonable use of <title> since it will appear in search > engines and in the title bar of the browser--but which would we say is > the 'real' title here? > > Regards, > > Mark > > On 31/08/2007, Karl Dubost <karl@w3.org> wrote: >> Hi, >> >> I would like to know if there's a rule for getting the meaning of >> this document. >> >> The XHTML document is located at >> http://example.org/foo/bar >> >> The markup is >> >> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN" >> "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd"> >> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> >> <head> >> <meta name="dc:title" content="The Old Man And The Sea, Ernest >> Hemingway" /> >> <title>The Old Man And The Sea - Literature</title> >> </head> >> <body> >> <h1>Book <span property="dc:title">The Old Man And The Sea, >> Hemingway</span></h1> >> </body> >> </html> >> >> >> Two solutions >> <> dc:title "The Old Man And The Sea, Ernest Hemingway"^^XMLLiteral . >> <> dc:title "The Old Man And The Sea, Hemingway"^^XMLLiteral . >> >> And another third one from the XHTML title element? >> (if title is considered to be dc:title. More on that later.) >> <> dc:title "The Old Man And The Sea - Literature"^^XMLLiteral . >> >> >> * Are there rules of precedence in RDFa? >> * Is there a need to explain the semantics conformance of HTML-like >> languages? >> >> >> >> -- >> Karl Dubost - http://www.w3.org/People/karl/ >> W3C Conformance Manager, QA Activity Lead >> QA Weblog - http://www.w3.org/QA/ >> *** Be Strict To Be Cool *** >> >> >> >> >> > >
Received on Friday, 31 August 2007 22:25:36 UTC