W3C home > Mailing lists > Public > public-rdfa-wg@w3.org > August 2011

Small modification proposal on my proposal...

From: Ivan Herman <ivan@w3.org>
Date: Thu, 11 Aug 2011 13:12:32 +0200
To: W3C RDFWA WG <public-rdfa-wg@w3.org>
Message-Id: <AE51ED85-5BD3-4AD1-951D-8167864F76CC@w3.org>
In [1] I proposed a more formal description for the new vocab feature:

[[[
- For all URI-s that appear as a value of a @vocab attribute in the RDFa source, that URI is dereferenced. If the dereferencing yields the serialization of an RDF graph, that graph is merged with the default graph. (RDFa processor MUST accept an RDF graph serialized in RDFa, SHOULD accept an RDF graph serialized in RDF/XML[REF] or Turtle[REF], and MAY accept other serialization formats of RDF.) 
- The processor expands the default graph using the RDFa Vocab Entailment @@@Link to section below@@@.
]]]

while correct, this algorithm has the (minor) downside that the output (a.k.a. default) graph will also contain the RDFS vocabularies themselves, too (ie, the content of the @vocab files). This is not a major issue, but it may increase the output of the default graph with triples that most of the users would not care. We could modify this a little bit

[[[
- A vocabulary graph is created as follows. Initially this graph is empty. For all URI-s that appear as a value of a @vocab attribute in the RDFa source, that URI is dereferenced. If the dereferencing yields the serialization of an RDF graph, that graph is merged with the vocabulary graph. (RDFa processor MUST accept an RDF graph serialized in RDFa, SHOULD accept an RDF graph serialized in RDF/XML[REF] or Turtle[REF], and MAY accept other serialization formats of RDF.) 
- The processor expands the merge of the default and vocabulary graphs using the RDFa Vocab Entailment @@@Link to section below@@@.
- The processor MAY remove the triples appearing in both the (expanded) default graph and the vocabulary graph from the default graph to reduce the size of that graph

Note that if, in the first step, a particular vocabulary is serialized in RDFa, that particular graph is not expected to undergo a similar vocabulary expansion on its own. This is to avoid unnecessary problems with recursion.
]]]

Essentially, it is allowed to remove the vocabulary statements from the output. I have also added a note on the issue of recursion.

Ivan




[1] http://lists.w3.org/Archives/Public/public-rdfa-wg/2011Aug/0007.html

----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Thursday, 11 August 2011 11:10:39 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:19:52 UTC