/ 
RDF-Trine-Shortcuts-0.02
/ RDF::Trine::Shortcuts

NAME

RDF::Trine::Shortcuts - totally unauthorised module for cheats and charlatans

VERSION

0.02

SYNOPSIS

use RDF::Trine::Shortcuts;

my $model = rdf_parse('http://example.com/data.rdf');
my $query = 'ASK WHERE {?person a <http://xmlns.com/foaf/0.1/Person>}';
if (rdf_query($query, $model))
{
  print "Document describes a person.\n";
}
else
{
  print "Document doesn't describe a person.\n";
  print "What does it describe? Let's see...\n";
  print rdf_string($model);
}

DESCRIPTION

This module exports three functions which simplify frequently performed tasks using RDF::Trine and RDF::Query.

In addition, because it calls "use RDF::Trine", "use RDF::Query", and "use RDF::Query::Client", your code doesn't need to.

rdf_parse($data)

$data can be some serialised RDF (in RDF/XML, Turtle, RDF/JSON, or any other format that RDF::Trine::Parser supports); or a URI (string or URI object); or an HTTP::Message object; or a hashref (as per RDF::Trine::Model's add_hashref method); or a file name or an open file handle; or an RDF::Trine::Iterator::Graph. Essentially it could be anything you could reasonably expect to grab RDF from. It can be undef.

The function returns an RDF::Trine::Model.

There are additional optional named arguments, of which the two most useful are probably 'base', which sets the base URI for any relative URI references; and 'type', which indicates the media type of the input (though the function can usually guess this quite reliably).

$model = rdf_parse($input,
                   'base' => 'http://example.com/',
                   'type' => 'application/rdf+xml');

Other named arguments include 'model' to provide an existing RDF::Trine::Model to add statements to; and 'context' for providing a context/graph URI (which may be a string, URI object or RDF::Trine::Node).

rdf_string($model, $format)

Serialises an RDF::Trine::Model to a string.

$model is the model to serialise. If $model is not an RDF::Trine::Model object, then it's automatically passed through rdf_parse first.

$format is the format to use. One of 'RDFXML' (the default), 'RDFJSON', 'Canonical NTriples' or 'NTriples'. If $format is not one of the above, then the function will try to guess what you meant.

rdf_query($sparql, $endpoint)

$sparql is a SPARQL query to be run at $endpoint.

$endpoint may be either an endpoint URI (string or URI object) or a model supported by RDF::Query (e.g. an RDF::Trine::Model.)

If the SPARQL query returns a boolean (i.e. an ASK query), then this function returns a boolean. If the query returns a graph (i.e. CONSTRUCT or DESCRIBE), then this function returns an RDF::Trine::Model corresponding to the graph. Otherwise (i.e. SELECT) it returns an RDF::Trine::Iterator object.

For queries which return a graph, an optional $model parameter can be passed containing an existing RDF::Trine::Model to add statements to:

rdf_parse("CONSTRUCT {?s ?p ?o} WHERE {?s ?p ?o}",
          'http://example.com/sparql',
          model => $model);

BUGS

Please report any bugs to http://rt.cpan.org/.

SEE ALSO

RDF::Trine, RDF::Query, RDF::Query::Client.

http://www.perlrdf.org/.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT

Copyright 2010 Toby Inkster

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.