Markup questions: html/body, datatype="", double predicates

Hi,

I'm getting my feet wet with RDFa authoring. So far, it's a nice  
enough experience, but I'm running into some issues that I cannot  
answer myself. I'm not sure if this is the best list to ask these  
questions, if there is a better one then please let me know.


I'm using the RDFa Distiller at
http://www.w3.org/2007/08/pyRdfa/
to look at the triples. My test file is here:
http://richard.cyganiak.de/2008/12/rdfa-test.html

My problems are the following.


1. Behaviour of RDFa markup on <html> and <body> elements. Let's say  
my file contains these markup bits (doctype, namespace declarations  
etc omitted):

<html rel="foaf:maker" rev="foaf:homepage">
   <body about="#me">
     ...

I expect this to generate these triples:

<> foaf:maker <#me> .
<#me> foaf:homepage <> .

But what I get from the RDFa Distiller:

<> foaf:maker <#me> .
<#me> foaf:homepage <> .
<> foaf:maker <> .
<> foaf:homepage <> .

Why is this?


2. Behaviour of datatype="" when the content includes *RDFa* markup.  
Let's say I have this in my HTML:

<p about="#me" property="bio:olb">
   I work at
   <a rel="foaf:workplaceHomepage" href="http://www.deri.ie/">DERI
   Galway</a>.
</p>

This works as expected, it creates two triples, a bio:olb triple whose  
value is an rdf:XMLLiteral, and a foaf:workplaceHomepage triple whose  
value is the DERI URL.

Now I want the bio:olb as a plain literal, so I add datatype="" to the  
<p> tag. This creates the expected plain literal, but the  
foaf:workplaceHomepage triple disappears. Annoying! Is this the  
correct result? I sort of hope that it's a bug in the RDFa Distiller...


3. Double predicates. Just to confirm, is it always allowed to have  
multiple CURIEs in the CURIE-accepting properties?

rel="foo:prop1 bar:prop2"
rev="foo:prop1 bar:prop2"
property="foo:prop1 bar:prop2"
typeof="foo:prop1 bar:prop2"

I assume that all of these are legal and will result in two triples  
instead of one?


That's all for now. Finally, in case that some of the folks who  
influenced the design of RDFa on this list: Let me say that I'm  
impressed with the result. Obviously a lot of thought went into every  
detail of the language and the result is pleasing and elegant.  
Finally, here's an RDF syntax that does not suck and makes RDF  
publishing fun!

Cheers,
Richard

Received on Tuesday, 9 December 2008 23:30:08 UTC