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Re: [RDFa] rdf:XMLLiteral (was RE: Missing issue on the list: identification of RDFa content)

From: Dan Brickley <danbri@danbri.org>
Date: Mon, 19 Mar 2007 00:05:34 +0000
Message-ID: <45FDD3CE.6060604@danbri.org>
To: mark.birbeck@x-port.net
Cc: Elias Torres <elias@torrez.us>, Ian Davis <iand@internetalchemy.org>, Ben Adida <ben@adida.net>, public-rdf-in-xhtml-tf@w3.org

Mark Birbeck wrote:
> Hi Elias/Ian,
> I'm afraid I'm missing from this discussion, first what we *lose* by
> using rdf:XMLLiteral, and second, some clear-cut explanation of why
> plain literals are *logically* the correct default, rather than just
> simply someone's 'preference'.

One brief but hopefully simple point: if RDFa generates literals that 
are typed XMLLiteral, ... RDFa document authors need to choose RDF 
vocabularies whose properties have that has a range.

Actually I'm not sure. They certainly need to consider the range.


"The class rdf:XMLLiteral is the class of XML literal values. 
rdf:XMLLiteral is an instance of rdfs:Datatype and a subclass of 

If we define a property to have a range rdfs:Literal, and it is 
generally used with plain literals... does anything get tricky if we 
start using it with rdf:XMLLiteral?

I have to admit, to date, I had assumed without scrutiny that this was 
problematic. I guess I had been confusing the superclass rdfs:Literal 
with the notion of a "plain Literal", 
... but it seems (unless I'm missing something; sorry I forget the 
design discussions! it was a while back now...) ...seems that we don't 
define a class for plain literals.

So, for example, we say foaf:name has a range

I had previously thought this made use of XMLLiteral in names 
problematic, eg. for ruby markup in names. But perhaps not.

A question (for the OWL folk here): if we have a property sometimes 
taking plain literals as values, and sometimes taking XMLLiteral, ... 
does this put the property (and hence vocab) into OWL Full?


Received on Monday, 19 March 2007 00:05:42 UTC

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