NAME

HTML::Selector::XPath - CSS Selector to XPath compiler

SYNOPSIS

  use HTML::Selector::XPath;
  my $selector = HTML::Selector::XPath->new("li#main");
  $selector->to_xpath; # //li[@id='main']
  # functional interface
  use HTML::Selector::XPath 'selector_to_xpath';
  my $xpath = selector_to_xpath('div.foo');
  my $relative = selector_to_xpath('div.foo', root => '/html/body/p' );
  # /html/body/p/div[contains(concat(' ', @class, ' '), ' foo ')]
  my $relative = selector_to_xpath('div:root', root => '/html/body/p' );
  # /html/body/p/div

DESCRIPTION

HTML::Selector::XPath is a utility function to compile full set of CSS2 and partial CSS3 selectors to the equivalent XPath expression.

FUNCTIONS and METHODS

selector_to_xpath

  $xpath = selector_to_xpath($selector, %options);

Shortcut for "HTML::Selector->new(shift)->to_xpath(@_)". Exported upon request.

new

  $sel = HTML::Selector::XPath->new($selector, %options);

Creates a new object.

to_xpath

  $xpath = $sel->to_xpath;
  $xpath = $sel->to_xpath(root => "."); # ./foo instead of //foo

Returns the translated XPath expression. You can optionally pass "root" parameter, to specify which root to start the expression. It defaults to "/".

The optional "prefix" option allows you to specify a namespace prefix for the generated XPath expression.

SUBCLASSING NOTES

parse_pseudo: This method is called during xpath construction when we encounter a pseudo selector (something that begins with comma). It is passed the selector and a reference to the string we are parsing. It should return one or more xpath sub-expressions to add to the parts if the selector is handled, otherwise return an empty list.

CAVEATS

CSS SELECTOR VALIDATION

This module doesn't validate whether the original CSS Selector expression is valid. For example,

  div.123foo

is an invalid CSS selector (class names should not begin with numbers), but this module ignores that and tries to generate an equivalent XPath expression anyway.

COPYRIGHT

Tatsuhiko Miyagawa 2006-2011

Max Maischein 2011-

AUTHOR

Tatsuhiko Miyagawa <miyagawa@bulknews.net>

Most of the logic is based on Joe Hewitt's getElementsBySelector.js on <http://www.joehewitt.com/blog/2006-03-20.php> and Andrew Dupont's patch to Prototype.js on <http://dev.rubyonrails.org/ticket/5171>, but slightly modified using Aristotle Pegaltzis' CSS to XPath translation table per <http://plasmasturm.org/log/444/>

Also see

<http://www.mail-archive.com/www-archive@w3.org/msg00906.html>

and

<http://kilianvalkhof.com/2008/css-xhtml/the-css3-not-selector/>

LICENSE

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