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Reification in RDFa Was: .htaccess a major bottleneck to Semantic Web adoption

From: Eric Hellman <openurl@gmail.com>
Date: Fri, 10 Jul 2009 23:00:56 -0400
Cc: Toby Inkster <tai@g5n.co.uk>, public-lod@w3.org
Message-Id: <CFCADA3C-6A8F-4CF3-A479-3836F8CF9531@gmail.com>
To: Mark Birbeck <mark.birbeck@webbackplane.com>
As my first attempt at producing RDFa, I tried some reification. Very  
verbose, but it worked:
http://go-to-hellman.blogspot.com/2009/05/reif-part-2-future-of-rdf-rdfa-and.html
I found the RDFa documentation to be very good. Thanks Mark.

Eric Hellman
President, Gluejar, Inc.
41 Watchung Plaza, #132
Montclair, NJ 07042
USA

eric@hellman.net
http://go-to-hellman.blogspot.com/

On Jun 29, 2009, at 9:48 AM, Mark Birbeck wrote:

> 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 Saturday, 11 July 2009 03:01:41 UTC

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