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HTML::Embedded::Turtle(3pm) User Contributed Perl Documentation HTML::Embedded::Turtle(3pm)

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.
"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.

2021-09-11 perl v5.32.1