RDF::TrineX::Functions - some shortcut functions for RDF::Trine's object-oriented interface
use RDF::TrineX::Functions -all; my $model = model(); parse('/tmp/mydata.rdf', into => $model); $model->add_statement(statement( iri('http://example.com/'), iri('http://purl.org/dc/terms/title'), "An Example", )); print RDF::Trine::Serializer -> new('Turtle') -> serialize_model_to_string($model);
This is a replacement for the venerable RDF::TrineShortcuts. Not a drop-in replacement. It has fewer features, fewer dependencies, less hackishness, less magic and fewer places it can go wrong.
It uses Sub::Exporter, which allows exported functions to be renamed easily:
use RDF::TrineX::Functions parse => { -as => 'parse_rdf' };
iri
literal
blank
variable
As per the similarly named functions exported by RDF::Trine itself.
These are wrapped with a very tiny bit of DWIMmery. A blessed URI object passed to iri will be handled properly; a blessed URI object passed to literal will default the datatype to xsd:anyURI. A string starting with "_:" passed to either iri or blank will correctly create a blank node. A string starting with "?" passed to either blank or variable will correctly create a variable. If any of them are passed an existing RDF::Trine::Node, it will be passed through untouched.
Other than that, no magic.
curie
Like iri but passes strings through RDF::NS::Trine.
statement(@nodes)
As per the similarly named function exported by RDF::Trine itself.
Again, a tiny bit of DWIMmery: blessed URI objects are passed through iri and unblessed scalars (i.e. strings) are assumed to be literals.
store
model
Returns a new RDF::Trine::Model. May be passed a store as a parameter.
parse($source, %options)
Parses the source and returns an RDF::Trine::Model. The source may be:
a URI
A string URI, blessed URI object or RDF::Trine::Node::Resource, which will be retrieved and parsed.
a file
A filehandle, Path::Class::File, IO::All, IO::Handle object, or the name of an existing file (i.e. a scalar string). The file will be read and parsed.
Except in the case of Path::Class::File, IO::All and strings, you need to tell the parse function what parser to use, and what base URI to use.
parse
a string
You need to tell the parse function what parser to use, and what base URI to use.
a model or store
An existing model or store, which will just be returned as-is.
undef
Returns an empty model.
The parser option can be used to provide a blessed RDF::Trine::Parser object to use; the type option can be used instead to provide a media type hint. The base option provides the base URI. The model option can be used to tell this function to parse into an existing model rather than returning a new one. The graph option may be used to provide a graph URI.
parser
type
base
graph
into is an alias for model; type, using and as are aliases for parser; context is an alias for graph.
into
using
as
context
Examples:
my $model = parse('/tmp/data.ttl', as => 'Turtle'); my $data = iri('http://example.com/data.nt'); my $parser = RDF::Trine::Parser::NTriples->new; my $model = model(); parse($data, using => $parser, into => $model);
serialize($data, %options)
Serializes the data (which can be an RDF::Trine::Model or an RDF::Trine::Iterator) and returns it as a string.
The serializer option can be used to provide a blessed RDF::Trine::Serializer object to use; the type option can be used instead to provide a type hint. The output option can be used to provide a filehandle, IO::All, Path::Class::File or file name to write to instead of returning the results as a string.
serializer
output
to and file are aliases for output; type, using and as are aliases for serializer.
to
file
print serialize($model, as => 'Turtle'); my $file = Path::Class::File->new('/tmp/data.nt'); serialize($iterator, to => $file, as => 'NTriples');
In addition to the above interface, each function supports being called with a single arrayref argument. In those cases, the arrayref is dereferenced into an array, and treated as a list of arguments. That is, the following are equivalent:
foo($bar, $baz); foo([$bar, $baz]);
This is handy if you're writing a module of your own and wish to accept some RDF data:
sub my_method { my ($self, $rdf, $foo) = @_; $rdf = parse($rdf); .... }
Your method can now be called like this:
$object->my_method($model, 'foo'); $object->my_method($url, 'foo'); $object->my_method( [ $filehandle, as => 'Turtle', base => $uri ], 'foo', );
By default, nothing is exported. You need to request things:
use RDF::TrineX::Functions qw< iri literal blank statement model >;
Thanks to Sub::Exporter, you can rename functions:
use RDF::TrineX::Functions qw< literal statement model >, blank => { -as => 'bnode' }, iri => { -as => 'resource' };
If you want to export everything, you can do:
use RDF::TrineX::Functions -all;
To export just the functions which generate RDF::Trine::Node objects:
use RDF::TrineX::Functions -nodes;
Or maybe even:
use RDF::TrineX::Functions -nodes => { -suffix => '_node' };
If you want to export something roughly compatible with the old RDF::TrineShortcuts, then there's:
use RDF::TrineX::Functions -shortcuts;
When exporting the serialize function you may set a default format:
serialize
use RDF::TrineX::Functions serialize => { -type => 'NTriples' };
This will be used when serialize is called with no explicit type given.
new
This acts as a constructor, returning a new RDF::TrineX::Functions object.
All the normal functions can be called as methods:
my $R = RDF::TrineX::Functions->new; my $model = $R->model;
There's no real advantage to using this module as an object, but it can help you avoid namespace pollution.
Please report any bugs to http://rt.cpan.org/Dist/Display.html?Queue=RDF-TrineX-Functions.
RDF::Trine, RDF::QueryX::Lazy, RDF::NS.
Toby Inkster <tobyink@cpan.org>.
This software is copyright (c) 2012 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
To install RDF::TrineX::Functions, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RDF::TrineX::Functions
CPAN shell
perl -MCPAN -e shell install RDF::TrineX::Functions
For more information on module installation, please visit the detailed CPAN module installation guide.