This recent discussion reminds me of a question that I have been wondering about for several months and hadn't gotten around to bringing up: can you have a Darwin Core XML representation where an element has a literal value and an attribute? If the XML is RDF, then I think the answer is pretty much "no" as I just found out with the W3C Validator. However, in generic XML I don't think there is any rule that says that one can't have any attribute that one wants. The only guidance I know of on the subject is: http://rs.tdwg.org/dwc/terms/guides/xml/index.htm#implement It states that the value of a Darwin Core property should be the content of the element rather than stating the value as an attribute. However, I have the situation where I want to store or transfer two somewhat equivalent representations of the value of a property: a string literal form and a URI form. In the example we've been talking about, I would like my generic (non-RDF) XML to do something like this:
<?xml version="1.0" encoding="UTF-8"?> <dwr:SimpleDarwinRecordSet xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dwc="http://rs.tdwg.org/dwc/terms/" xmlns:dwr="http://rs.tdwg.org/dwc/xsd/simpledarwincore/" > dwr:SimpleDarwinRecord <dwc:occurrenceID rdf:resource="http://herbarium.org/hb123456%22%3Ehttp://herbarium.org/hb123456</dwc:occurrenceID> <dwc:recordedBy rdf:resource="http://people.vanderbilt.edu/~steve.baskauf/foaf.rdf#me%22%3ESteve Baskauf</dwc:recordedBy> <dwc:basisOfRecord rdf:resource="http://rs.tdwg.org/dwc/dwctype/PreservedSpecimen%22%3EPreservedSpecimen</dwc:basisOfRecord> ... more elements, mostly with string literal values... </dwr:SimpleDarwinRecord> </dwr:SimpleDarwinRecordSet>
This would meet the basic guidelines of the Darwin Core XML Guide in that the literal values would be the contents of the elements. What I don't know is if the inclusion of the rdf:resource attributes would invalidate the XML if it were validated against someone's schema that was silent about attributes or if the schema would have to explicitly say that having an rdf:resource attribute was a valid option. I think I don't know enough about XML schemas ...
The reason why I would like to maintain/transfer both types of values (literal and URI) is so that I could use the XML data to generate both HTML and RDF if I wanted. The HTML would tell humans that the occurrence was a PreservedSpecimen, but the RDF would tell a linked data client that the occurrence was a http://rs.tdwg.org/dwc/dwctype/PreservedSpecimen . I realize that for my own internal use, the XML can have any format I want, but if I were exporting XML for general public use, would it be bad to use the approach above?
Steve
As an aside, I wanted to see exactly what the definition was for rdf:resource However, the usual namespace for rdf: (http://www.w3.org/1999/02/22-rdf-syntax-ns#) doesn't seem to include "resource" in the defined properties. Very odd! Maybe I'm just missing something...