SIMPLE SOLUTIONS

RDF::TRINEX::FUNCTIONS(3PM) - man page online | library functions

Some shortcut functions for RDF::Trine's object-oriented interface.

Chapter
2014-09-10
RDF::TrineX::Functions(3pm)    User Contributed Perl Documentation    RDF::TrineX::Functions(3pm)

NAME

RDF::TrineX::Functions - some shortcut functions for RDF::Trine's object-oriented interface

SYNOPSIS

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);

DESCRIPTION

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' }; Functions "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" As per the similarly named function exported by RDF::Trine itself. "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. · 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. "into" is an alias for "model"; "type", "using" and "as" are aliases for "parser"; "context" is an alias for "graph". 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. "to" and "file" are aliases for "output"; "type", "using" and "as" are aliases for "serializer". Examples: print serialize($model, as => 'Turtle'); my $file = Path::Class::File->new('/tmp/data.nt'); serialize($iterator, to => $file, as => 'NTriples'); Array References In addition to the above interface, each function supports being called with a single arrayref argument. In those cases, the arrayref is dereferenced into an array, and treated as a list of arguments. That is, the following are equivalent: foo($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', ); Export 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: use RDF::TrineX::Functions serialize => { -type => 'NTriples' }; This will be used when "serialize" is called with no explicit type given. Pseudo-OO interface "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.

BUGS

Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=RDF-TrineX-Functions>.

SEE ALSO

RDF::Trine, RDF::QueryX::Lazy, RDF::NS.

AUTHOR

Toby Inkster <@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.

DISCLAIMER OF WARRANTIES

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.
perl v5.20.1 2014-09-10 RDF::TrineX::Functions(3pm)