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Re: DCMI Metadata Terms - request for help with RDF schemas

From: Gregg Kellogg <gregg@greggkellogg.net>
Date: Tue, 22 May 2012 09:38:26 -0400
To: Thomas Baker <tom@tombaker.org>
CC: public-rdfa <public-rdfa@w3.org>
Message-ID: <186D9901-B81A-4E3B-BE01-8A8957AA5BC5@kellogg-assoc.com>
On May 21, 2012, at 4:03 PM, "Thomas Baker" <tom@tombaker.org> wrote:

> Gregg, all,
> 
> Jon and I are working hard to get DCMI Metadata Terms published ASAP.  We are
> currently focusing on content negotiation.  We plan to redirect all PURLs to a
> directory such as http://dublincore.org/2012-05-21.  Jon has written an
> .htaccess file for that directory that would direct incoming requests for the
> four "namespace" schemas -- Turtle by default, RDF/XML by request -- and
> requests for HTML to /documents/dcmi-terms/.  Jon is working on some
> Javascript, to be embedded in http://dublincore.org/documents/dcmi-terms/,
> which would take the browser to the spot in the document where the requested
> term is described.
> 
> This will take some additional testing before it goes live, but we're
> optimistic.
> 
> In the meantime, we would appreciate some help in fixing three little problems
> in the scripts that generate the RDF schemas [1]:
> 
> -- One triple, not yet supported by the scripts, is missing:
>   <http://purl.org/dc/terms/creator> owl:equivalentProperty <http://xmlns.com/foaf/0.1/maker>
> 
>   The source that would need to be supported is at [2], the script that 
>   needs fixing is (I think!) at [3].

Easy enough.

> -- Dates are not fully qualified with datatypes (as they are in the RDFa/HTML document.
>   For example, the schemas say:
> 
>       <http://purl.org/dc/terms/valid> dcterms:issued "2000-07-11" .
> 
>   instead of 
> 
>       <http://purl.org/dc/terms/valid> dcterms:issued "2000-07-11"^^<http://www.w3.org/2001/XMLSchema#date> .

The output uses the time element, which supports automatic date format detection. The processors currently supporting this can be found in the RDFa EARL report [9] and include my own, Ivan's pyRdfa and Niklas' clj-rdfa, but this is in an unreleased spec and is probably not widely supported right now.

I used this, so that @datatype is not necessary; @datatype is not in RDFa Lite. If your group concurs, I can add back in the @datatype="xls:date", but it will ultimately be unnecessary.

> -- Two of the RDF schemas generated from the scripts express redundant triples (see
>   below).  This problem appears to have two aspects:
> 
>   1) The script is apparently outputting malformed XML (look closely at line 16 in 
>      dcam.rdf) [8] but neither Jon nor I know XSL well enough to see why.
> 
>   2) In both dcelements.rdf and dcam.rdf, the RDF/XML says:
> 
>        <rdf:Property rdf:about="http://purl.org/dc/elements/1.1/creator">
>        <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
> 
>      whereas in dctype.rdf and dcterms.rdf, the RDF/XML says:
> 
>        <rdf:Description rdf:about="http://purl.org/dc/terms/creator">
>        <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
> 
>      This would account for the "redundant triples", but neither Jon nor I can see how
>      the scripts are leading to these different results.

I'll see what I can do.

Gregg

> We would much appreciate help in this.
> 
> Many thanks,
> Tom
> 
> [1] https://github.com/dublincore/website/tree/master/build
> [2] https://github.com/dublincore/website/blob/master/2012-05-21/xmldata/dcterms-properties.xml#L64
> [3] https://github.com/dublincore/website/blob/master/web/xsl/dcelements.xsl
> [4] https://github.com/dublincore/website/blob/master/build/dcelements.rdf
> [5] https://github.com/dublincore/website/blob/master/build/dcam.rdf
> [6] https://github.com/dublincore/website/blob/master/build/dcelements.rdf
> [7] http://rdf.greggkellogg.net/distiller?format=ntriples&in_fmt=rdfxml&uri=https://raw.github.com/dublincore/website/master/build/dcelements.rdf
> [8] https://github.com/dublincore/website/blob/master/build/dcam.rdf#L1
[9] http://rdfa.info/earl-reports/#xhtml5 test 0272
> 
> ----------------------------------------------------------------------
> Redundant triples generated from [4]
> 
>    <http://purl.org/dc/dcam/VocabularyEncodingScheme>  rdf:type rdfs:Class .
>    <http://purl.org/dc/dcam/memberOf>                  rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/contributor>       rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/coverage>          rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/creator>           rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/date>              rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/description>       rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/format>            rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/identifier>        rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/language>          rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/publisher>         rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/relation>          rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/rights>            rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/source>            rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/subject>           rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/title>             rdf:type rdf:Property .
>    <http://purl.org/dc/elements/1.1/type>              rdf:type rdf:Property .
> 
> 
> -- 
> Tom Baker <tom@tombaker.org>
> 
Received on Tuesday, 22 May 2012 13:43:22 GMT

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