# XML::NamespaceSupport - phpMan

## NAME
    [XML::NamespaceSupport] - A simple generic namespace processor

## VERSION
    version 1.12

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

## NAME
    [XML::NamespaceSupport] - a simple generic namespace support class

## 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 (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

## 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

## SEE ALSO
    [XML::Parser::PerlSAX]

## AUTHORS
    *   Robin Berjon <<robin@knowscape.com>>

    *   Chris Prather <<chris@prather.org>>

## COPYRIGHT AND LICENSE
    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.

## CONTRIBUTORS
    *   Chris Prather <<cprather@hdpublishing.com>>

    *   David Steinbrunner <<dsteinbrunner@pobox.com>>

    *   Paul Cochrane <<paul@liekut.de>>

    *   Paulo Custodio <<pauloscustodio@gmail.com>>

