W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > October 2004

4.3.4.2 hasReferenceTo

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Tue, 26 Oct 2004 16:41:02 +0100
Message-ID: <417E700E.5060608@hplb.hpl.hp.com>
To: public-rdf-in-xhtml-tf <public-rdf-in-xhtml-tf@w3.org>


This seems a bit problematic ...

[[
4.3.4.2 Using "hasReferenceTo"
If the predicate is omitted, and the [context statement] also has no 
predicate, then a default value of "hasReferenceTo" is used if the 
object is a [literal]. The most common usage of this syntax is to 
indicate that some text in a document actually has a useful value that 
is different to the actual text. Through this mechanism it is possible 
to provide normalised values, such as dates, names for countries and 
people, and so on.
]]

Thinking about implementing, it seems that the key to implementation is 
to find all the rel, rev and property attributes and generate triple(s) 
for each of them.

Quite what needs to be present to trigger a hasReferenceTo default ...
All elements have (possibly empty) content, which could be the object of 
a triple, all elements have a context statement which can provide a subject.

I think what may be meant is that if there is a @content  then there is 
a default value for @property of "hasReferenceTo", and if there is an 
@href then there is a default value for @rel of "hasReferenceTo" (with 
open issue as to whether these two defaults should be the same or 
different - I vote for different).
This default is complicated by it not applying if the parent element has 
  the appropriate attribute (this seems mistaken, since the 4.4.3 
provision uses the *subject* of the current element, not its *object*).


Suggestions:

1) Make it explicit that this para applies only where there is an @href 
or @content

2) Delete
"and the [context statement] also has no predicate,"


Also necessary, as noted in RDF/A, to provide example to motivate this. 
It certainly makes implementation harder ...

Jeremy
Received on Tuesday, 26 October 2004 15:41:19 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:14:59 GMT