/ 
HTML-HTML5-Outline-0.006
River stage one • 1 direct dependent • 1 total dependent
/ HTML::HTML5::Outline

NAME

HTML::HTML5::Outline - implementation of the HTML5 Outline algorithm

SYNOPSIS

use JSON;
use HTML::HTML5::Outline;

my $html = <<'HTML';
<!doctype html>
<h1>Hello</h1>
<h2>World</h2>
<h1>Good Morning</h1>
<h2>Vietnam</h2>
HTML

my $outline = HTML::HTML5::Outline->new($html);
print to_json($outline->to_hashref, {pretty=>1,canonical=>1});

DESCRIPTION

This is an implementation of the HTML5 Outline algorithm, as per http://www.w3.org/TR/html5/sections.html#outlines.

The module can output a JSON-friendly hashref, or an RDF model.

Constructor

  • HTML::HTML5::Outline->new($html, %options)

    Construct a new outline. $html is the HTML to generate an outline from, either as an HTML or XHTML string, or as an XML::LibXML::Document object.

    Options:

    • default_language - default language to assume text is in when no lang/xml:lang attribute is available. e.g. 'en-gb'.

    • element_subjects - rather advanced feature that doesn't bear explaining. See USE WITH RDF::RDFA::PARSER for an example.

    • microformats - support <ul class="xoxo">, <ol class="xoxo"> and <whatever class="figure"> as sectioning elements (like <section>, <figure>, etc). Boolean, defaults to false.

    • parser - 'html' (default) or 'xml' - choose the parser to use for XHTML/HTML. If the constructor is passed an XML::LibXML::Document, this is ignored.

    • suppress_collections - allows rdf:List stuff to be suppressed from RDF output. RDF output - especially in Turtle format - looks somewhat nicer without them, but if you care about the order of headings and sections, then you'll want them. Boolean, defaults to false.

    • uri - the document URI for resolving relative URI references. Only really used by the RDF output.

Object Methods

  • to_hashref

    Returns data as a nested hashref/arrayref structure. Dump it as JSON and you'll figure out the format pretty easily.

  • to_rdf

    Returns data as a n RDF::Trine::Model. Requires RDF::Trine to be installed. Otherwise this method won't exist.

  • primary_outlinee

    Returns a HTML::HTML5::Outline::Outlinee element representing the outline for the page.

Class Methods

  • has_rdf

    Indicates whether the to_rdf object method exists.

USE WITH RDF::RDFA::PARSER

This module produces RDF data where many of the resources described are HTML elements. RDFa data typically does not, but RDF::RDFa::Parser does also support some extensions to RDFa which do (e.g. support for the cite and role attributes). It's useful to combine the RDF data from each, and RDF::RDFa::Parser 1.093 and upwards contains a few shims to make this possible.

Without further ado...

use HTML::HTML5::Outline;
use RDF::RDFa::Parser 1.093;
use RDF::TrineShortcuts;

my $rdfa = RDF::RDFa::Parser->new(
	$html_source,
	$base_url,
	RDF::RDFa::Parser::Config->new(
		'html5', '1.1',
		role_attr     => 1,
		cite_attr     => 1,
		longdesc_attr => 1,
		),
	)->consume;

my $outline = HTML::HTML5::Outline->new(
	$rdfa->dom,
	uri              => $rdfa->uri,
	element_subjects => $rdfa->element_subjects,
	);

# Merging two graphs is pretty complicated in RDF::Trine
# but a little easier with RDF::TrineShortcuts...
my $combined = rdf_parse();
rdf_parse($rdfa->graph,     model => $combined);
rdf_parse($outline->to_rdf, model => $combined);

my $NS = {
	dc    => 'http://purl.org/dc/terms/',
	o     => 'http://ontologi.es/outline#',
	type  => 'http://purl.org/dc/dcmitype/',
	xs    => 'http://www.w3.org/2001/XMLSchema#',
	xhv   => 'http://www.w3.org/1999/xhtml/vocab#',
	};

print rdf_string($combined => 'Turtle', namespaces => $NS);

SEE ALSO

HTML::HTML5::Outline::RDF, HTML::HTML5::Outline::Outlinee, HTML::HTML5::Outline::Section.

HTML::HTML5::Parser, HTML::HTML5::Sanity.

AUTHOR

Toby Inkster, <tobyink@cpan.org>

ACKNOWLEDGEMENTS

This module is a fork of the document structure parser from Swignition <http://buzzword.org.uk/swignition/>.

That in turn includes the following credits: thanks to Ryan King and Geoffrey Sneddon for pointing me towards [the HTML5] algorithm. I also used Geoffrey's python implementation as a crib sheet to help me figure out what was supposed to happen when the HTML5 spec was ambiguous.

COPYRIGHT AND LICENCE

Copyright (C) 2008-2011 by Toby Inkster

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.