HTML::Embedded::Turtle - embedding RDF in HTML the crazy way
use HTML::Embedded::Turtle; my $het = HTML::Embedded::Turtle->new($html, $base_uri); foreach my $graph ($het->endorsements) { my $model = $het->graph($graph); # $model is an RDF::Trine::Model. Do something with it. }
RDF can be embedded in (X)HTML using simple <script> tags. This is described at http://esw.w3.org/N3inHTML. This gives you a file format that can contain multiple (optionally named) graphs. The document as a whole can "endorse" a graph by including:
<link rel="meta" href="#foo" />
Where "#foo" is a fragment identifier pointing to a graph.
<script type="text/turtle" id="foo"> ... </script>
The rel="meta" stuff is parsed using an RDFa parser, so equivalent RDFa works too.
This module parses HTML files containing graphs like these, and allows you to access them each individually; as a union of all graphs on the page; or as a union of just the endorsed graphs.
Despite the module name, this module supports a variety of <script type>s: text/turtle, application/turtle, application/x-turtle text/plain (N-Triples), text/n3 (Notation 3), application/x-rdf+json (RDF/JSON), application/json (RDF/JSON), and application/rdf+xml (RDF/XML).
The deprecated attribute "language" is also supported:
<script language="Turtle" id="foo"> ... </script>
Languages supported are (case insensitive): "Turtle", "NTriples", "RDFJSON", "RDFXML" and "Notation3".
HTML::Embedded::Turtle->new($markup, $base_uri, \%opts)
Create a new object. $markup is the HTML or XHTML markup to parse; $base_uri is the base URI to use for relative references.
Options include:
markup
Choose which parser to use: 'html' or 'xml'. The former chooses HTML::HTML5::Parser, which can handle tag soup; the latter chooses XML::LibXML, which cannot. Defaults to 'html'.
rdfa_options
A set of options to be parsed to RDF::RDFa::Parser when looking for endorsements. See RDF::RDFa::Parser::Config. The default is probably sensible.
union_graph
A union graph of all graphs found in the document, as an RDF::Trine::Model. Note that the returned model contains quads.
endorsed_union_graph
A union graph of only the endorsed graphs, as an RDF::Trine::Model. Note that the returned model contains quads.
graph($name)
A single graph from the page.
graphs
all_graphs
A hashref where the keys are graph names and the values are RDF::Trine::Models. Some graph names will be URIs, and others may be blank nodes (e.g. "_:foobar").
graphs and all_graphs are aliases for each other.
endorsed_graphs
Like all_graphs, but only returns endorsed graphs. Note that all endorsed graphs will have graph names that are URIs.
endorsements
Returns a list of URIs which are the names of endorsed graphs. Note that the presence of a URI $x in this list does not imply that $het->graph($x) will be defined.
$x
$het->graph($x)
dom
Returns the page DOM.
uri
Returns the page URI.
Please report any bugs to http://rt.cpan.org/.
Please forgive me in advance for inflicting this module upon you.
RDF::RDFa::Parser, RDF::Trine, RDF::TriN3.
http://www.perlrdf.org/.
Toby Inkster <tobyink@cpan.org>.
Copyright (C) 2010-2011, 2013 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 HTML::Embedded::Turtle, copy and paste the appropriate command in to your terminal.
cpanm
cpanm HTML::Embedded::Turtle
CPAN shell
perl -MCPAN -e shell install HTML::Embedded::Turtle
For more information on module installation, please visit the detailed CPAN module installation guide.