Manpages - XML_LibXML_Pattern.3pm

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

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);

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.

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

Matt Sergeant, Christian Glahn, Petr Pajas

2.0207

2001-2007, AxKit.com Ltd.

2002-2006, Christian Glahn.

2006-2009, Petr Pajas.

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