Re: Subtle namespace difference with RDFa+HTML5 for XML Literals...

On Mar 9, 2012, at 9:32 AM, Ivan Herman wrote:

> Test #198:
> 
> <!DOCTYPE html>
> <html 
> xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>> 
>  <head>
> 	<title>Test 0198</title>
> 	<base href="http://www.example.org/me" />
> </head>
> <body>
>      <div id="mark" about="#mark" typeof="foaf:Person">
>        <h2 property="foaf:name" datatype="rdf:XMLLiteral"><span 
> property="foaf:firstName">Mark</span> <span 
> property="foaf:surname">Birbeck</span></h2>
>      </div>
> </body>
> </html>
> 
> With a SPARQL request:
> 
> ASK WHERE {
> <http://www.example.org/me#mark> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> .
> <http://www.example.org/me#mark> <http://xmlns.com/foaf/0.1/name>
> "<span property=\"foaf:firstName\" xmlns=\"http://www.w3.org/1999/xhtml\" xmlns:foaf=\"http://xmlns.com/foaf/0.1/\" xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">Mark</span> <span property=\"foaf:surname\" xmlns=\"http://www.w3.org/1999/xhtml\" xmlns:foaf=\"http://xmlns.com/foaf/0.1/\" xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">Birbeck</span>"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral> .
> <http://www.example.org/me#mark> <http://xmlns.com/foaf/0.1/firstName> "Mark" .
> <http://www.example.org/me#mark> <http://xmlns.com/foaf/0.1/surname> "Birbeck" .
> }
> 
> However. While it is o.k. to have the rdf and foaf namespaces copied into the generated XML Literal, the  xmlns="http://www.w3.org/1999/xhtml" is actually incorrect. In the case of XHTML1 this namespace indeed appears in the file, can therefore be copied into the XMLLiteral, ie, that test is o.k. for XHTML1+RDFa, that namespace does *not* appear for HTML5, ie, it should not be added to the XML Literal.

Have I mentioned that I hate XMLLiterals?

> We can create a separate test for HTML5+RDFa, doing the same but with a different SPARQL. On the other hand, in view of the controversial nature of the xmlns usage in HTML5, I would probably be o.k. to remove it from the HTML5 branch altogether.

This is really where an HTMLLiteral would make sense, and use that for HTML5 instead of XMLLiteral. As I understand it, polyglot markup, where xmlns would be appropriate, would only make sense for XHTML5, not HTML5. I'd suggest we remove HTML5 (and HTML4, I suppose) from anything using xml:lang or xmlns (with the exception of the stated use of xml:lang as a namespace-less attribute, which I'd rather see go away from HTML5+RDFa). If work is ever done on HTMLLiteral (RDF WG?), then we could include this for HTML5, and it would probably be appropriate for XHTML varieties as well).

> I am not sure about XHTML5. Does the namespace appears for that one? If so, it is fine to have it for that one...

Being XML, I believe that xmlns is appropriate).

Gregg

> Ivan
> 
> 
> 
> ----
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> FOAF: http://www.ivan-herman.net/foaf.rdf
> 
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Received on Friday, 9 March 2012 16:52:49 UTC