XML::NamespaceSupport - A simple generic namespace processor

       •   Robin Berjon <robin@knowscape.com>

       •   Chris Prather <chris@prather.org>

       •   Chris Prather <cprather@hdpublishing.com>

       •   David Steinbrunner <dsteinbrunner@pobox.com>

       •   Paul Cochrane <paul@liekut.de>

       •   Paulo Custodio <pauloscustodio@gmail.com>

perl v5.34.0                                       2022-06-28                         XML::NamespaceSupport(3pm)

       This software is copyright (c) 2015 by Robin Berjon.

       This is free software; you can redistribute it and/or modify it under  the  same  terms  as  the  Perl  5
       programming language system itself.

       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.saxproject.org/namespaces.html It adds a few perlisations where we thought it appropriate.

       •   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 (i.e. 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 a 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 a 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.

           Note  that  at least one context must be added to the stack via "push_context" before this method can
           be called.

       •   $nsup->get_uri($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               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

       XML::NamespaceSupport - a simple generic namespace support class

       XML::Parser::PerlSAX

         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');

        - add more tests
        - optimise here and there

       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.

       version 1.12