XML::NamespaceSupport - a simple generic namespace support class
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');
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.
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.
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.
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
.
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
.
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
.
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
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
$NS_XML
- add more tests - optimise here and there
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 (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.
XML::Parser::PerlSAX