html::selector::xpath(3pm) [debian man page]

HTML::Selector::XPath(3pm)				User Contributed Perl Documentation				HTML::Selector::XPath(3pm)

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

       and

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

SEE ALSO

       http://www.w3.org/TR/REC-CSS2/selector.html <http://www.w3.org/TR/REC-CSS2/selector.html> <http://use.perl.org/~miyagawa/journal/31090>

perl v5.14.2							    2012-01-16						HTML::Selector::XPath(3pm)

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XML::LibXML::Pattern(3) 				User Contributed Perl Documentation				   XML::LibXML::Pattern(3)

NAME

       XML::LibXML::Pattern - XML::LibXML::Pattern - interface to libxml2 XPath patterns

SYNOPSIS

	 use XML::LibXML;
	 my $pattern = XML::LibXML::Pattern->new('/x:html/x:body//x:div', { 'x' => 'http://www.w3.org/1999/xhtml' });
	 # test a match on an XML::LibXML::Node $node

	 if ($pattern->matchesNode($node)) { ... }

	 # or on an XML::LibXML::Reader

	 if ($reader->matchesPattern($pattern)) { ... }

	 # or skip reading all nodes that do not match

	 print $reader->nodePath while $reader->nextPatternMatch($pattern);

	 $pattern = XML::LibXML::Pattern->new( pattern, { prefix => namespace_URI, ... } );
	 $bool = $pattern->matchesNode($node);

DESCRIPTION

       This is a perl interface to libxml2's pattern matching support http://xmlsoft.org/html/libxml-pattern.html. This feature requires recent
       versions of libxml2.

       Patterns are a small subset of XPath language, which is limited to (disjunctions of) location paths involving the child and descendant axes
       in abbreviated form as described by the extended BNF given below:

	 Selector ::=	  Path ( '|' Path )*
	 Path	  ::=	  ('.//' | '//' | '/' )? Step ( '/' Step )*
	 Step	  ::=	  '.' | NameTest
	 NameTest ::=	  QName | '*' | NCName ':' '*'

       For readability, whitespace may be used in selector XPath expressions even though not explicitly allowed by the grammar: whitespace may be
       freely added within patterns before or after any token, where

	 token	   ::=	   '.' | '/' | '//' | '|' | NameTest

       Note that no predicates or attribute tests are allowed.

       Patterns are particularly useful for stream parsing provided via the "XML::LibXML::Reader" interface.

       new()
	     $pattern = XML::LibXML::Pattern->new( pattern, { prefix => namespace_URI, ... } );

	   The constructor of a pattern takes a pattern expression (as described by the BNF grammar above) and an optional HASH reference mapping
	   prefixes to namespace URIs. The method returns a compiled pattern object.

	   Note that if the document has a default namespace, it must still be given an prefix in order to be matched (as demanded by the XPath
	   1.0 specification). For example, to match an element "<a xmlns="http://foo.bar"</a>", one should use a pattern like this:

	     $pattern = XML::LibXML::Pattern->new( 'foo:a', { foo => 'http://foo.bar' });

       matchesNode($node)
	     $bool = $pattern->matchesNode($node);

	   Given an XML::LibXML::Node object, returns a true value if the node is matched by the compiled pattern expression.

SEE ALSO

       XML::LibXML::Reader for other methods involving compiled patterns.

AUTHORS

       Matt Sergeant, Christian Glahn, Petr Pajas

VERSION

       2.0008

COPYRIGHT

       2001-2007, AxKit.com Ltd.

       2002-2006, Christian Glahn.

       2006-2009, Petr Pajas.

perl v5.16.2							    2012-10-22						   XML::LibXML::Pattern(3)

Linux and UNIX Man Pages

html::selector::xpath(3pm) [debian man page]

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