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XML::NamespaceSupport(3)             User Contributed Perl Documentation            XML::NamespaceSupport(3)



NAME
       XML::NamespaceSupport - a simple generic namespace support class

SYNOPSIS
         use XML::NamespaceSupport;
         my $nsup = XML::NamespaceSupport->new;

         # add a new empty context
         $nsup->push_context;
         # declare a few prefixes
         $nsup->declare_prefix($prefix1, $uri1);
         $nsup->declare_prefix($prefix2, $uri2);
         # the same shorter
         $nsup->declare_prefixes($prefix1 => $uri1, $prefix2 => $uri2);

         # get a single prefix for a URI (randomly)
         $prefix = $nsup->get_prefix($uri);
         # get all prefixes for a URI (probably better)
         @prefixes = $nsup->get_prefixes($uri);
         # get all prefixes in scope
         @prefixes = $nsup->get_prefixes();
         # get all prefixes that were declared for the current scope
         @prefixes = $nsup->get_declared_prefixes;
         # get a URI for a given prefix
         $uri = $nsup->get_uri($prefix);

         # get info on a qname (java-ish way, it's a bit weird)
         ($ns_uri, $local_name, $qname) = $nsup->process_name($qname, $is_attr);
         # the same, more perlish
         ($ns_uri, $prefix, $local_name) = $nsup->process_element_name($qname);
         ($ns_uri, $prefix, $local_name) = $nsup->process_attribute_name($qname);

         # remove the current context
         $nsup->pop_context;

         # reset the object for reuse in another document
         $nsup->reset;

         # a simple helper to process Clarkian Notation
         my ($ns, $lname) = $nsup->parse_jclark_notation('{http://foo}bar');
         # or (given that it doesn't care about the object
         my ($ns, $lname) = XML::NamespaceSupport->parse_jclark_notation('{http://foo}bar');

DESCRIPTION
       This module offers a simple to process namespaced XML names (unames) from within any application that
       may need them. It also helps maintain a prefix to namespace URI map, and provides a number of basic
       checks.

       The model for this module is SAX2's NamespaceSupport class, readable at
       http://www.megginson.com/SAX/Java/javadoc/org/xml/sax/helpers/NamespaceSupport.html.  It adds a few
       perlisations where we thought it appropriate.

METHODS
       •   XML::NamespaceSupport->new(\%options)

           A simple constructor.

           The options are "xmlns", "fatal_errors", and "auto_prefix"

           If "xmlns" is turned on (it is off by default) the mapping from the xmlns prefix to the URI
           defined for it in DOM level 2 is added to the list of predefined mappings (which normally only
           contains the xml prefix mapping).

           If "fatal_errors" is turned off (it is on by default) a number of validity errors will simply be
           flagged as failures, instead of die()ing.

           If "auto_prefix" is turned on (it is off by default) when one provides a prefix of "undef" to
           "declare_prefix" it will generate a random prefix mapped to that namespace. Otherwise an undef
           prefix will trigger a warning (you should probably know what you're doing if you turn this option
           on).

           If "xmlns_11" us turned off, it becomes illegal to undeclare namespace prefixes. It is on by
           default. This behaviour is compliant with Namespaces in XML 1.1, turning it off reverts you to
           version 1.0.

       •   $nsup->push_context

           Adds a new empty context to the stack. You can then populate it with new prefixes defined at this
           level.

       •   $nsup->pop_context

           Removes the topmost context in the stack and reverts to the previous one. It will die() if you
           try to pop more than you have pushed.

       •   $nsup->declare_prefix($prefix, $uri)

           Declares a mapping of $prefix to $uri, at the current level.

           Note that with "auto_prefix" turned on, if you declare a prefix mapping in which $prefix is
           undef(), you will get an automatic prefix selected for you. If it is off you will get a warning.

           This is useful when you deal with code that hasn't kept prefixes around and need to reserialize
           the nodes. It also means that if you want to set the default namespace (ie with an empty prefix)
           you must use the empty string instead of undef. This behaviour is consistent with the SAX 2.0
           specification.

       •   $nsup->declare_prefixes(%prefixes2uris)

           Declares a mapping of several prefixes to URIs, at the current level.

       •   $nsup->get_prefix($uri)

           Returns a prefix given an URI. Note that as several prefixes may be mapped to the same URI, it
           returns an arbitrary one. It'll return undef on failure.

       •   $nsup->get_prefixes($uri)

           Returns an array of prefixes given an URI. It'll return all the prefixes if the uri is undef.

       •   $nsup->get_declared_prefixes

           Returns an array of all the prefixes that have been declared within this context, ie those that
           were declared on the last element, not those that were declared above and are simply in scope.

       •   $nsup->get_uri($prefix)

           Returns a URI for a given prefix. Returns undef on failure.

       •   $nsup->process_name($qname, $is_attr)

           Given a qualified name and a boolean indicating whether this is an attribute or another type of
           name (those are differently affected by default namespaces), it returns a namespace URI, local
           name, qualified name tuple. I know that that is a rather abnormal list to return, but it is so
           for compatibility with the Java spec. See below for more Perlish alternatives.

           If the prefix is not declared, or if the name is not valid, it'll either die or return undef
           depending on the current setting of "fatal_errors".

       •   $nsup->undeclare_prefix($prefix);

           Removes a namespace prefix from the current context. This function may be used in SAX's
           end_prefix_mapping when there is fear that a namespace declaration might be available outside
           their scope (which shouldn't normally happen, but you never know ;). This may be needed in order
           to properly support Namespace 1.1.

       •   $nsup->process_element_name($qname)

           Given a qualified name, it returns a namespace URI, prefix, and local name tuple. This method
           applies to element names.

           If the prefix is not declared, or if the name is not valid, it'll either die or return undef
           depending on the current setting of "fatal_errors".

       •   $nsup->process_attribute_name($qname)

           Given a qualified name, it returns a namespace URI, prefix, and local name tuple. This method
           applies to attribute names.

           If the prefix is not declared, or if the name is not valid, it'll either die or return undef
           depending on the current setting of "fatal_errors".

       •   $nsup->reset

           Resets the object so that it can be reused on another document.

       All methods of the interface have an alias that is the name used in the original Java specification.
       You can use either name interchangeably. Here is the mapping:

         Java name                 Perl name
         ---------------------------------------------------pushContext --------------------------------------------------pushContext
         pushContext               push_context
         popContext                pop_context
         declarePrefix             declare_prefix
         declarePrefixes           declare_prefixes
         getPrefix                 get_prefix
         getPrefixes               get_prefixes
         getDeclaredPrefixes       get_declared_prefixes
         getURI                    get_uri
         processName               process_name
         processElementName        process_element_name
         processAttributeName      process_attribute_name
         parseJClarkNotation       parse_jclark_notation
         undeclarePrefix           undeclare_prefix

VARIABLES
       Two global variables are made available to you. They used to be constants but simple scalars are
       easier to use in a number of contexts. They are not exported but can easily be accessed from any
       package, or copied into it.

       •   $NS_XMLNS

           The namespace for xmlns prefixes, http://www.w3.org/2000/xmlns/.

       •   $NS_XML

           The namespace for xml prefixes, http://www.w3.org/XML/1998/namespace.

TODO
        - add more tests
        - optimise here and there

AUTHOR
       Robin Berjon, robin@knowscape.com, with lots of it having been done by Duncan Cameron, and a number
       of suggestions from the perl-xml list.

COPYRIGHT
       Copyright (c) 2001-2005 Robin Berjon. All rights reserved. This program is free software; you can
       redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO
       XML::Parser::PerlSAX



perl v5.12.5                                     2010-03-16                         XML::NamespaceSupport(3)