NAME

    RDF::Simple::Serialiser

DESCRIPTION

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

SYNOPSIS

    my $ser = RDF::Simple::Serialiser->new;

    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']
                   );

    my $rdf = $ser->serialise(@triples);

    ##
    ## supply own bNode id prefix, add namespaces

    my $ser = RDF::Simple::Serialiser->new( nodeid_prefix => 'a:' );

    $ser->addns( foaf => 'http://xmlns.com/foaf/0.1/' );

    my $node1 = $ser->genid;
    my $node2 = $ser->genid;

    my @triples = (
                   [$node1, 'foaf:name', 'Jo Walsh'],
                   [$node1, 'foaf:knows', $node2],
                   [$node2, 'foaf:name', 'Robin Berjon'],
                   [$node1, 'rdf:type', 'foaf:Person'],
                   [$node2, 'rdf:type','http://xmlns.com/foaf/0.1/Person']
                   );

    my $rdf = $ser->serialise(@triples);

    ##
    ## round-trip

    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( [ 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.

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.

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

    add new namespaces to the RDF document.
    a namespace must exist for each predicate used in a triple.
    the RDF::Simple::NS module which supports this one
    provides the following vocabularies by default
    (you can override them if wished)

        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/",

BUGS

    Probably still some left, this is a beta release. feedback very welcome.

NOTES

    I am English, so this is a Serialiser. for our divided friends across the water, RDF::Simple::Serializer will work as an alias to the module, and serialize() does the same as serialise().
 
    Neither parser or serialiser makes an effort to differentiate formally between URIs and literals, as is more general RDF practise. This was a conscious effort to keep things simple, but i plan to add a make_life_complex option to both.

THANKS

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

AUTHOR

    jo walsh <jo@london.pm.org>

LICENSE

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