- From: Chris Lilley <chris@w3.org>
- Date: Wed, 23 Mar 2005 20:33:40 +0100
- To: Dan Connolly <connolly@w3.org>
- Cc: RDF in XHTML task force <public-rdf-in-xhtml-tf@w3.org>
On Wednesday, March 23, 2005, 8:11:33 PM, Dan wrote: DC> On Mon, 2005-03-21 at 15:55 +0100, Chris Lilley wrote: >> Hello public-rdf-in-xhtml-tf, >> >> In section 3 of GRDDL (I was reading the 13 April 2004 version) >> http://www.w3.org/TR/grddl/#grddl-xml >> >> The first two paragraphs seem to contradict each other >> >> >> The GRDDL profile mechanism is a special case of GRDDL designed to >> >> fit within the syntax of XHTML 1.0. The general form of GRDDL is an >> >> attribute suitable for use with a wide variety of XML dialects. >> >> OK, cool, so I read on to find out how to do that ... >> >> >> Use of the interpreter attribute in the >> >> http://www.w3.org/2003/g/data-view# namespace on the root element of >> >> an XML document indicates that RDF statements that result from >> >> transformation of the HTML document to RDF by designated algorithms >> >> are part of the document's meaning. >> >> "the HTML document"? What if my XML is *not* HTML? Is 'the HTML >> document' just a typo? DC> yes... fixed in DC> http://www.w3.org/2004/01/rdxh/spec#grddl-xml DC> $Revision: 1.58 $ Thanks >> To be specific, how would I change this example >> http://www.w3.org/TR/SVG11/metadata.html#Example >> >> to say that the content of the metadata element is part of the documents >> meaning? Do I merely add >> >> xmlns:grddl="http://www.w3.org/2003/g/data-view#" >> grddl:interpreter="what, exactly, goes here" DC> yes... DC> xmlns:data-view="http://www.w3.org/2003/g/data-view#" DC> DC> data-view:transformation="http://www.w3.org/2003/g/embeddedRDF.xsl" Ok so transformation, not interpreter. DC> You can see the result at DC> http://www.w3.org/2003/g/svgc-ex/svg_meta_ex.svg DC> It works with http://www.w3.org/2003/g/svgc-ex/glean.py ala... DC> $ python glean.py --output ,svgm.rdf DC> http://www.w3.org/2003/g/svgc-ex/svg_meta_ex.svg DC> xsltproc spews complaints about the SVG namespace document DC> (it's HTML, not XHTML) Really? (goes to fix that) DC> but you can disregard those diagnostics; DC> the resulting ,svgm.rdf has the right answer. (I hope we'll DC> upgrade the SVG namespace document to RDDL or the like soon.) Yes, good idea. DC> I tried it in the online service... DC> http://www.w3.org/2004/01/rdxh/grddl-xml-demo DC> but I it fails in a way that I don't understand. (Dom?) >> I read >> >> The value of the grddl:interpreter attribute designates a list of >> >> algorithms by URI reference >> >> It seems to point to an xsl stylesheet, not a list of algorithms. DC> As Dom explained, an XSLT stylesheet is a representation of DC> an algorithm. An, yes - its not a list, or at least, only a very short one. >> I would also like to know how to GRDDLize these examples >> >> http://www.w3.org/TR/SVG11/coords.html#GeographicCoordinates >> >> if that turns out to be different. DC> Not much. I did the 1st and 2nd ones... DC> http://www.w3.org/2003/g/svgc-ex/coord_meta1.svg DC> http://www.w3.org/2003/g/svgc-ex/coord_meta2.svg DC> On the 3rd one I get an RDF parsing error... DC> RDF.RedlandError: property element 'CoordinateReferenceSystem' has DC> multiple object node elements, skipping. Hmm. Is that an issue with your code or an issue with our RDF? >> Please note also that SVG is structured, so a single SVG document >> instance can have several logical parts and each of these can have its >> own metadata element. How do I indicate that the metadata applies to >> just a particular part of the document (ie, the parent of the metadata >> element? DC> RDF is context-free... the subjects of the statements are explicit. DC> the rdf:about attribute is used to say what statements are about. DC> In the 2nd example, I see this bit of RDF: DC> <rdf:Description> DC> <!-- In case of a well-known Coordinate Reference System DC> an 'Identifier' is enough to describe the CRS --> DC> <crs:CoordinateReferenceSystem DC> svg:transform="rotate(-90) scale(100, 100)"> DC> <crs:Identifier> DC> That just says "there is a coordinate reference system." It doesn't DC> say what the relationship between that coordinate system and this DC> SVG file is. Suggestions on how to fix that? Its supposed to say 'here is a coordinate system' and 'here is a projection' and 'this svg file represents a map in that coordinate system with that projection'. It seems we are missing the RDFese, or the GRDDLese, to make the third statement. -- Chris Lilley mailto:chris@w3.org Chair, W3C SVG Working Group W3C Graphics Activity Lead
Received on Wednesday, 23 March 2005 19:33:42 UTC