xml::libxml::pattern(3pm) [debian man page]
XML::LibXML::Pattern(3pm) User Contributed Perl Documentation XML::LibXML::Pattern(3pm) 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
2.0001 COPYRIGHT
2001-2007, AxKit.com Ltd. 2002-2006, Christian Glahn. 2006-2009, Petr Pajas. perl v5.14.2 2012-06-20 XML::LibXML::Pattern(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)