RDF::Trine(3) An RDF Framework for Perl


This document describes RDF::Trine version 1.014


use RDF::Trine;

my $store = RDF::Trine::Store::Memory->new();
my $model = RDF::Trine::Model->new($store);

# parse some web data into the model, and print the count of resulting RDF statements
RDF::Trine::Parser->parse_url_into_model( 'http://kasei.us/about/foaf.xrdf', $model );
print $model->size . " RDF statements parsed\n";

# Create a namespace object for the foaf vocabulary
my $foaf = RDF::Trine::Namespace->new( 'http://xmlns.com/foaf/0.1/' );

# Create a node object for the FOAF name property
my $pred = $foaf->name;
# alternatively:
# my $pred = RDF::Trine::Node::Resource->new('http://xmlns.com/foaf/0.1/name');

# Create an iterator for all the statements in the model with foaf:name as the predicate
my $iter = $model->get_statements(undef, $pred, undef);

# Now print the results
print "Names of things:\n";
while (my $st = $iter->next) {
my $s = $st->subject;
my $name = $st->object;

# $s and $name have string overloading, so will print correctly
print "The name of $s is $name\n";


RDF::Trine provides an Resource Descriptive Framework (RDF) with an emphasis on extensibility, API stability, and the presence of a test suite. The package consists of several components:
  • RDF::Trine::Model - RDF model providing access to a triple store. This module would typically be used to access an existing store by a developer looking to ``Just get stuff done.''
  • RDF::Trine::Parser - RDF parsers for various serialization formats including RDF/XML, Turtle, RDFa, and RDF/JSON.
  • RDF::Trine::Store::Memory - An in-memory, non-persistant triple store. Typically used for temporary data.
  • RDF::Trine::Store::DBI - A triple store for MySQL, PostgreSQL, and SQLite, based on the relational schema used by Redland. Typically used to for large, persistent data.
  • RDF::Trine::Iterator - Iterator classes for variable bindings and RDF statements, used by RDF::Trine::Store, RDF::Trine::Model, and RDF::Query.
  • RDF::Trine::Namespace - A convenience class for easily constructing RDF::Trine::Node::Resource objects from URI namespaces.


"iri ( $iri )"
Returns a RDF::Trine::Node::Resource object with the given IRI value.
"blank ( $id )"
Returns a RDF::Trine::Node::Blank object with the given identifier.
"literal ( $value, $lang, $dt )"
Returns a RDF::Trine::Node::Literal object with the given value and optional language/datatype.
"variable ( $name )"
Returns a RDF::Trine::Node::Variable object with the given variable name.
"statement ( @nodes )"
Returns a RDF::Trine::Statement object with the supplied node objects.
"store ( $config )"
Returns a RDF::Trine::Store object based on the supplied configuration string.
"default_useragent ( [ $ua ] )"
Returns the LWP::UserAgent object used by default for any operation requiring network requests. Ordinarily, the calling code will obtain the default user agent, and clone it before further configuring it for a specific request, thus leaving the default object untouched.

If $ua is passed as an argument, sets the global default user agent to this object.


Please report any bugs or feature requests to through the GitHub web interface at <https://github.com/kasei/perlrdf/issues>.


Gregory Todd Williams "<[email protected]>"


Copyright (c) 2006-2012 Gregory Todd Williams. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.