Monthly Archives: September 2010

RdfContext and RDF::RDFa support for RDFa 1.1 2008-08-03 draft semantics

 I’ve updated both RdfContext and RDF::RDFa gems to support the latest RDFa Core 1.1 Editor’s Draft  (2010-08-03) semantics. This includes support for the following:

  • Use of a Processor Graph to gather information and errors during the course of parsing. Use the :processor_graph option to specify a Graph in which to collect information. There is no published specification for the properties to use, but until there is, each event is saved with a Blank Node subject of type rdfa.UndefinedPrefixError, rdfa:UndefinedTermError, rdfa:HostLanguageMarkupError, rdfa:ProfileReferenceError, rdfa:InformationalMessage, rdfa;MiscellaneousWarning or rdfa:MiscellaneousError. Additionally statements with literals for dc:description, dc:date, rdfa:sequence and rdfa:source (path to HTML Node) are generated.
  • RDFa Profiles allow URI mappings for terms and prefixes along with the specification of a default vocabulary.
  • RDFa 1.1 prefixes the use of @prefix to create prefix mappings, but @xmlns continues to be supported.
  • XMLLiterals must be declared explicitly by setting @datatype=”rdf:XMLLiteral”. In 1.0, any statement with a property that contained anything other than text nodes as children caused an XMLLiteral to be emitted.

Note that until RDFa Core 1.1 is published, all features are subject to change. I will not be attempting to maintain compatibility with draft features that are obsoleted during the standardization process.