RDF::Generator::Void(3) Generate VoID descriptions based on data in an RDF model


Version 0.16


use RDF::Generator::Void;
use RDF::Trine::Model;
my $mymodel = RDF::Trine::Model->temporary_model;
[add some data to $mymodel here]
my $generator = RDF::Generator::Void->new(inmodel => $mymodel);
my $voidmodel = $generator->generate;


This module takes a RDF::Trine::Model object as input to the constructor, and based on the data in that model as well as data supplied by the user, it creates a new model with a VoID description of the data in the model.

For a description of VoID, see <http://www.w3.org/TR/void/>.


new(inmodel => $mymodel, dataset_uri => URI->new($dataset_uri), level => 1);

The constructor. It can be called with two parameters, namely, "inmodel" which is a model we want to describe and "dataset_uri", which is the URI we want to use for the description. Users should make sure it is possible to get this with HTTP. If this is not possible, you may leave this field empty so that a simple URN can be created for you as a default.


Read-only accessor for the model used in description creation.


Read-only accessor for the URI to the dataset.

Property Attributes

The below attributes concern some essential properties in the VoID vocabulary. They are mostly arrays, and can be manipulated using array methods. Methods starting with "all_" will return an array of unique values. Methods starting with "add_" takes a list of values to add, and those starting with "has_no_" return a boolean value, false if the array is empty.

"all_vocabularies", "add_vocabularies", "has_no_vocabularies"

Methods to manipulate a list of vocabularies used in the dataset. The values should be a string that represents the URI of a vocabulary.

"all_endpoints", "add_endpoints", "has_no_endpoints"

Methods to manipulate a list of SPARQL endpoints that can be used to query the dataset. The values should be a string that represents the URI of a SPARQL endpoint.

"all_titles", "add_titles", "has_no_titles"

Methods to manipulate the titles of the datasets. The values should be RDF::Trine::Node::Literal objects, and should be set with language. Typically, you would have a value per language.

"all_licenses", "add_licenses", "has_no_licenses"

Methods to manipulate a list of licenses that regulates the use of the dataset. The values should be a string that represents the URI of a license.

"urispace", "has_urispace"

This method is used to set the URI prefix string that will match the entities in your dataset. The computation of the number of entities depends on this being set. "has_urispace" can be used to check if it is set.

Running this stuff

"level", "has_level"

Set the level of detail. 0 doesn't do any statistics or heuristics, 1 has some statistics for the dataset as a whole, 2 will give some partition statistics and 3 will give subject and object counts for property partitions. Setting no level will give everything.

"stats", "clear_stats", "has_stats"

Method to compute a statistical summary for the data in the dataset, such as the number of entities, predicates, etc. "clear_stats" will clear the statistics and "has_stats" will return true if exists.

generate( [ $model ] )

Returns the VoID as an RDF::Trine::Model. You may pass a model with statements as argument to this method. This model may then contain arbitrary RDF that will be added to the RDF model. If you do not send a model, one will be created for you.


Kjetil Kjernsmo "<[email protected]>" Toby Inkster "<[email protected]>"


  • URI regexps support.
  • Technical features (esp. serializations).
  • Example resources and root resources.
  • Data dumps.
  • Subject classification.
  • Method to disable heuristics.
  • More heuristics.
  • Linkset descriptions.
  • Set URI space on partitions.
  • Use CHI to cache?
  • Use schema introspection to generate property attributes with MooseX::Semantic.


Please report any bugs you find to <https://github.com/kjetilk/RDF-Generator-Void/issues>

Note that any claim that this module will generate a void in spacetime, a wormhole, black hole, or funny philosophy is totally bogus and without any scientific merit whatsoever. The lead author has made elaborate precautions to avoid any such issues, and expects everyone to take his word for it. Oh, BTW, should it just happen anyway, it won't hurt much <http://news.sciencemag.org/sciencenow/2012/03/scienceshot-one-black-hole-wont-.html>.


You can find documentation for this module with the perldoc command.

    perldoc RDF::Generator::Void

The Perl and RDF community website is at <http://www.perlrdf.org/> where you can also find a mailing list to direct questions to.

You can also look for information at:


Many thanks to Konstantin Baierer for help with RDF::Generator::Void::Meta::Attribute::ObjectList.


Copyright 2012 Toby Inkster. Copyright 2012,2013,2016 Kjetil Kjernsmo.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.