- From: Stéphane Corlosquet <scorlosquet@gmail.com>
- Date: Thu, 6 Sep 2012 02:26:43 -0400
- To: RDFa WG <public-rdfa-wg@w3.org>
- Message-ID: <CAGR+nnHdHJpJGNGDkv9WLEW2OrYRvBPsYr8J5n=x6qbrq4K1mg@mail.gmail.com>
The aim of ISSUE-135 is to prevent a non-RDFa @rel to disable the new behavior of @property in RDFa+HTML5. In HTML5, @rel is used for many purposes ([1] and [2]), many of them are irrelevant to RDFa. When HTML authors use these values in @rel, they most likely don't do it with RDFa in mind, and in this context the behavior of @property should not change when a non-RDFa @rel is added to the same element. In other words, the following two paragraphs should generate the same triples: <p vocab="http://schema.org/" typeof="Person"> My name is <a href="http://example.com/" property="homepage">Stephane Corlosquet</a>. </p> <p vocab="http://schema.org/" typeof="Person"> My name is <a href="http://example.com/" property="homepage" rel="me">Stephane Corlosquet</a>. </p> This issue has been discussed on the mailing list [3] and then during the call on May 10th [4]. The following two options were discussed on the call: 1) If you have an element that has both @rel and @property in HTML5, then the @rel can only take CURIEs, which will result in things like rel="nofollow" being ignored 2) There is a more global one that in HTML5+RDFa a @rel value can only have CURIEs. The following resolution was taken (essentially option 1): "If @property and @rel/@rev are on the same elements, the non-CURIE and non-URI @rel/@rev values are ignored. If, after this, the value of @rel/@rev becomes empty, then the then the processor must act as if the attribute is not present." This resolution ensures that rel="license" on an element with no @property is still supported. Here is a quick survey of some authoritative sites which are using or promoting rel="license". I found that very few are combining @property with @rel in the same element, and when they do, they always use cc:license in @rel. In other words, I could not find any example that would break with the option choosen above. Here are the sources I looked at: # No use of @property and @rel in the same element: A random wikipedia page: http://en.wikipedia.org/wiki/The_Garden_of_Forking_Paths A random Flickr page: http://www.flickr.com/photos/60223652@N00/2677272571/ http://microformats.org/wiki/rel-license http://www.alistapart.com/articles/introduction-to-rdfa/ http://reference.sitepoint.com/html/rel-mf # Use of @property and @rel in the same element using CURIEs: http://wiki.creativecommons.org/RDFa http://labs.creativecommons.org/2011/ccrel-guide/ http://labs.creativecommons.org/2011/ccrel-guide/examples/multiple_textimage.html http://wiki.creativecommons.org/License_Deeds_%28Metadata%29 # Use of @property and rel="license": *none* Steph. [1] http://www.w3.org/TR/html5-author/links.html#linkTypes [2] http://microformats.org/wiki/existing-rel-values [3] http://www.w3.org/2010/02/rdfa/track/issues/135 [4] http://www.w3.org/2010/02/rdfa/meetings/2012-05-10#ISSUE__2d_135__3a__RDFa_Lite_and_non__2d_RDFa___40_rel_values
Received on Thursday, 6 September 2012 06:32:52 UTC