- From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
- Date: Sat, 14 Aug 2010 14:01:05 +0200
- To: Ivan Herman <ivan@w3.org>
- Cc: public-rdfa-wg@w3.org
Ivan Herman, Sat, 14 Aug 2010 07:30:52 +0200: > It is of course _possible_ to extend the (X)HTML+RDFa attribute set > by interpreting @longdesc the way you suggest. Ie, > > <img src="*" longdesc="long.html" alt="short description" /> > > could be considered as a short hand for > > <img src="i.src" rel="longdesc" resource="long.html" property="alt" > content="short description" /> From RDFa's point of view, then it is perhaps better to assume this micro format, rather than the one I suggested ... > Generating triples for the i.src URI. As see, I extended that to the > @alt attribute, too; I am not sure how I would justify doing that for > longdesc and not doing it for @alt. > > The only thing I am a little bit concerned, I must admit, is not the > technical issue but the approach taken, ie, that we push RDFa into > interpreting new attributes for a very specific purposes. If we go > down that line, I am afraid of opening up flood gates (well, very > small ones, but nevertheless), which would bloat the RDFa spec. Eg, > we do not interpret the various attributes of the <object> element, I > am not sure what the new <video> and <audio> elements would bring, > etc. I understand this "flood gates" argument, of course ... > Note that registering the longdesc (and alt) as 'terms' as we call > them in RDFa, ie, as specific and predefined property/rel types, is > much easier to do and we are in the process of defining the mechanism > and the content to do that for HTML or XHTML. Ie, that can be done > easily, and no matter what. But what this means is that the users > would have to manually write the <img> elements the way I wrote them > up there. The IMG element you presented above was lacking both the longdesc attribute (you replaced it with a resource attribute). And it also lacked the alt attribute (you replaced it with a content attribute). Perhaps you could show a complete example with BOTH the @longdesc and @alt attributes in addition to the RDFa attributes that are necessary? Leif > Cheers > > Ivan > > > On Aug 14, 2010, at 04:58 , Leif Halvard Silli wrote: > >> There is a debate in the HTMLwg about the longdesc attribute. And in >> that debate, the thought has surfaced that @longdesc, >> >> <img src="*" longdesc="long.html" alt="short description" /> >> >> is simply a *shorthand notation* for this (hypothetical) micro format >> >> <a href="long.html" rel="longdesc"> >> <img src="*" alt="short description" /> >> </a> >> >> This has resulted in an attempt to register the 'longdesc' as link >> relation. [1] Simultaneously, a search for a better documentation of >> implementations of @longdesc has been (re)started. And in that context, >> I raised a question about RDFa and @longdesc. [2] >> >> Observation 1: The XHTML+RDFa DOCTYPE supports the @longdesc >> attribute. >> Observation 2: Mark Birbeck states in his 'Introduction to RDFa' >> article that «The @rel and @href attributes are no longer confined to >> the a and link elements, but can also be used on img to indicate a >> relationship between the image and some other item.» [3] >> Observation 3: A longdesc link indicates a relation between a short >> description and a long description. (See the quotes from HTML4 provided >> in [1]: 'link to long description (complements alt)' and 'link to long >> description (complements title)'.) >> >> Questions: Would it not be logical if RDFa treated the @longdesc link >> as a semantic link - e.g. equivalent to the micro format I described >> above? What needs to be added in order to make this happen? >> >> [1] >> http://www.ietf.org/mail-archive/web/link-relations/current/msg00047.html >> [2] http://lists.w3.org/Archives/Public/public-html/2010Aug/0140 >> [3] http://www.alistapart.com/articles/introduction-to-rdfa/ >> -- >> leif halvard silli >> > > > ---- > Ivan Herman, W3C Semantic Web Activity Lead > Home: http://www.w3.org/People/Ivan/ > mobile: +31-641044153 > PGP Key: http://www.ivan-herman.net/pgpkey.html > FOAF: http://www.ivan-herman.net/foaf.rdf > > > > >
Received on Saturday, 14 August 2010 12:01:41 UTC