NAME

RDF::Simple::Serialiser - convert a list of triples to RDF

DESCRIPTION

A simple RDF serialiser. Accepts an array of triples, returns a serialised RDF document.

SYNOPSIS

my $ser = RDF::Simple::Serialiser->new(
  # OPTIONAL: Supply your own bNode id prefix:
  nodeid_prefix => 'a:',
  );
# OPTIONAL: Add your namespaces:
$ser->addns(
            foaf => 'http://xmlns.com/foaf/0.1/',
           );
my $node1 = $ser->genid;
my $node2 = $ser->genid;
my @triples = (
               ['http://example.com/url#', 'dc:creator', 'zool@example.com'],
               ['http://example.com/url#', 'foaf:Topic', '_id:1234'],
               ['_id:1234','http://www.w3.org/2003/01/geo/wgs84_pos#lat','51.334422']
               [$node1, 'foaf:name', 'Jo Walsh'],
               [$node1, 'foaf:knows', $node2],
               [$node2, 'foaf:name', 'Robin Berjon'],
               [$node1, 'rdf:type', 'foaf:Person'],
               [$node2, 'rdf:type','http://xmlns.com/foaf/0.1/Person']
               [$node2, 'foaf:url', \'http://server.com/NOT/an/rdf/uri.html'],
              );
my $rdf = $ser->serialise(@triples);

## Round-trip example:
my $parser = RDF::Simple::Parser->new();
my $rdf = LWP::Simple::get('http://www.zooleika.org.uk/foaf.rdf');
my @triples = $parser->parse_rdf($rdf);
my $new_rdf = $serialiser->serialise(@triples);

METHODS

new()

new(nodeid_prefix => 'prefix')

serialise( @triples )

Accepts a 'bucket of triples' (an array of array references which are [subject, predicate, object] statements) and returns a serialised RDF document.

If 'rdf:type' is not provided for a subject, the generic node type 'rdf:Description' is used.

serialize

A synonym for serialise() for American users.

addns( qname => 'http://example.com/rdf/vocabulary#', qname2 => 'http://yetanother.org/vocabulary/' )

Use this method to add new namespaces to the RDF document. The RDF::Simple::NS module provides the following vocabularies by default (you can override them if you wish):

foaf    => 'http://xmlns.com/foaf/0.1/',
dc      => 'http://purl.org/dc/elements/1.1/',
rdfs    => 'http://www.w3.org/2000/01/rdf-schema#',
daml    => 'http://www.w3.org/2001/10/daml+oil#',
space   => 'http://frot.org/space/0.1/',
geo     => 'http://www.w3.org/2003/01/geo/wgs84_pos#',
rdf     => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
owl     => 'http://www.w3.org/2002/07/owl#',
ical    => 'http://www.w3.org/2002/12/cal/ical#',
dcterms => 'http://purl.org/dc/terms/',
wiki    => 'http://purl.org/rss/1.0/modules/wiki/',
chefmoz => 'http://chefmoz.org/rdf/elements/1.0/',

genid( )

generates a random identifier for use as a bNode (anonymous node) nodeID. if nodeid_prefix is set, the generated id uses the prefix, followed by 8 random numbers.

render

Does the heavy lifting of converting the "objects" to a string. Users of this module should call serialize(); Subclassers of this module will probably rewrite render().

BUGS

Please report bugs via the RT web site http://rt.cpan.org/Ticket/Create.html?Queue=RDF-Simple

NOTES

The original author was British, so this is a Serialiser. For American programmers, RDF::Simple::Serializer will work as an alias to the module, and serialize() does the same as serialise().

The distinction between a URI and a literal string in the "object" (third element) of each triple is made as follows: if the object is a reference, it is output as a literal; if the object "looks like" a URI (according to Regexp::Common::URI), it is output as a URI.

THANKS

Thanks particularly to Tom Hukins, and also to Paul Mison, for providing patches.

AUTHOR

Originally written by Jo Walsh (formerly <jo@london.pm.org>). Currently maintained by Martin Thurn <mthurn@cpan.org>.

LICENSE

This module is available under the same terms as perl itself.