- From: Mark Birbeck <mark.birbeck@webbackplane.com>
- Date: Mon, 29 Jun 2009 14:48:00 +0100
- To: Toby Inkster <tai@g5n.co.uk>
- Cc: public-lod@w3.org, semantic-web at W3C <semantic-web@w3c.org>
Hi Toby, Yes...of course...you are right. :) I would say too, that reification is even more long-winded than the example you have given! You don't have the actual statement "the sky is blue" in your mark-up, so you need even more RDFa. (You only have the statement "Mark says 'the sky is blue'".) But either way, you are right that the whole thing can be spelt out longhand (as can lists). The only reason I mentioned it was because for a long time in RDFa we had a much simpler construct based on occurrences of *nested* <meta> and <link> properties. However, some browsers thought they were doing us a favour by moving the <meta> and <link> elements out of the <body> and into the <head>, which meant it was not possible to implement this feature in JavaScript. (Obviously server-side RDFa parsers would have had no problem with it.) As for lists, the obvious shorthand would be <ol>, <ul>, and <li>, but it was not obvious what triples should be generated, so we left it. I.e., your example uses the first/next/nil technique for collections, but of course there is also the rdf:_1 technique for a list. It wasn't immediately clear which would be the more useful -- or conformant -- one to generate. Regards, Mark On Mon, Jun 29, 2009 at 2:05 PM, Toby Inkster<tai@g5n.co.uk> wrote: > On Mon, 2009-06-29 at 13:30 +0100, Mark Birbeck wrote: >> If we go back a step, RDFa was carefully designed so that it could >> carry any combination of the RDF concepts in an HTML document. In the >> end we dropped reification and lists, because it didn't seem that the >> RDF community itself was clear on the future of those, but they are >> both easily added back if the issues were to be resolved. > > RDF reification and lists do *work* in RDFa, they're just a bit of a > pain to mark up. > > e.g. here's a reification: > > <div xmlns:dc="http://purl.org/dc/elements/1.1/" > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" > xmlns:db="http://dbpedia.org/resource/" > typeof="rdf:Statement"> > <span property="dc:creator">Mark Birkbeck</span> says that > <span rel="rdf:subject" resource="[db:Sky]">the sky</span> > <span rel="rdf:predicate" resource="http://dbpedia.org/property/color" > >is</span> > <span rel="rdf:object" resource="[db:Blue]">blue</span>. > </div> > > And an example of a list can be found here: > > http://ontologi.es/rail/routes/gb/VTB1.xhtml > > -- > Toby A Inkster > <mailto:mail@tobyinkster.co.uk> > <http://tobyinkster.co.uk> > > -- Mark Birbeck, webBackplane mark.birbeck@webBackplane.com http://webBackplane.com/mark-birbeck webBackplane is a trading name of Backplane Ltd. (company number 05972288, registered office: 2nd Floor, 69/85 Tabernacle Street, London, EC2A 4RR)
Received on Monday, 29 June 2009 13:48:48 UTC