NAME¶
XML::Namespace - Simple support for XML Namespaces
SYNOPSIS¶
Example 1: using XML::Namespace objects
use XML::Namespace;
my $xsd = XML::Namespace->new('http://www.w3.org/2001/XMLSchema#');
# explicit access via the uri() method
print $xsd->uri(); # http://www.w3.org/2001/XMLSchema#
print $xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
# implicit access through AUTOLOAD method
print $xsd->integer; # http://www.w3.org/2001/XMLSchema#integer
Example 2: importing XML::Namespace objects
use XML::Namespace
xsd => 'http://www.w3.org/2001/XMLSchema#',
rdf => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
# xsd and rdf are imported subroutines that return
# XML::Namespace objects which can be used as above
print xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
print xsd->integer; # http://www.w3.org/2001/XMLSchema#integer
DESCRIPTION¶
This module implements a simple object for representing XML Namespaces in Perl.
It provides little more than some syntactic sugar for your Perl programs,
saving you the bother of typing lots of long-winded URIs. It was inspired by
the Class::RDF::NS module distributed as part of Class::RDF.
Using XML::Namespace Objects¶
First load the XML::Namespace module.
use XML::Namespace;
Then create an XML::Namespace object.
my $xsd = XML::Namespace->new('http://www.w3.org/2001/XMLSchema#');
Then use the
uri() method to return an absolute URI from a relative path.
print $xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
Alternately, use the AUTOLOAD method to map method calls to the
uri()
method.
print $xsd->integer; # http://www.w3.org/2001/XMLSchema#integer
Importing XML::Namespace Objects¶
When you "use" the XML::Namespace module, you can specify a list of
namespace definitions.
use XML::Namespace
xsd => 'http://www.w3.org/2001/XMLSchema#',
rdf => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
This defines the "xsd" and "rdf" subroutines and exports
them into the calling package. The subroutines simply return XML::Namespace
objects initialised with the relevant namespace URIs.
print xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
print xsd->integer; # http://www.w3.org/2001/XMLSchema#integer
Overloaded Stringification Method¶
The XML::Namespace module overloads the stringification operator to return the
namespace URI.
my $xsd = XML::Namespace->new('http://www.w3.org/2001/XMLSchema#');
print $xsd; # http://www.w3.org/2001/XMLSchema#
METHODS¶
new($uri)¶
Constructor method which creates a new XML::Namespace object. It expects a
single argument denoting the URI that the namespace is to represent.
use XML::Namespace;
my $xsd = XML::Namespace->new('http://www.w3.org/2001/XMLSchema#');
uri($path)¶
When called without arguments, this method returns the URI of the namespace
object, as defined by the argument passed to the
new() constructor
method.
$xsd->uri(); # http://www.w3.org/2001/XMLSchema#
An argument can be passed to indicate a path relative to the namespace URI. The
method returns a simple concatenation of the namespace URI and the relative
path argument.
$xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
import($name,$uri,$name,$uri,...)¶
This method is provided to work with the Exporter mechanism. It expects a list
of "($name, $uri)" pairs as arguments. It creates XML::Namespace
objects and accessor subroutines that are then exported to the caller's
package.
Although not intended for manual invocation, there's nothing to stop you from
doing it.
use XML::Namespace;
XML::Namespace->import( xsd => 'http://www.w3.org/2001/XMLSchema#' );
xsd()->integer; # http://www.w3.org/2001/XMLSchema#integer
Note that the parentheses are required when accessing this subroutine.
xsd()->integer; # Good
xsd->integer; # Bad
Unlike those that are defined automatically by the Importer, Perl doesn't know
anything about these subroutines at compile time. Without the parentheses,
Perl will think you're trying to call the "integer" method on an
unknown "xsd" package and you'll see an error like:
Can't locate object method "integer" via package "xsd"
That's why it's better to define your namespaces when you load the
XML::Namespace module.
use XML::Namespace
xsd => 'http://www.w3.org/2001/XMLSchema#';
xsd->integer; # Good
AUTOLOAD¶
The module defines an AUTOLOAD method that maps all other method calls to the
uri() method. Thus, the following return the same value.
$xsd->uri('integer'); # http://www.w3.org/2001/XMLSchema#integer
$xsd->integer; # http://www.w3.org/2001/XMLSchema#integer
AUTHOR¶
Andy Wardley <mailto:abw@cpan.org>
VERSION¶
This is version 0.02 of XML::Namespace.
COPYRIGHT¶
Copyright (C) 2005 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the
same terms as Perl itself.
SEE ALSO¶
The Class::RDF::NS module, distributed as part of Class::RDF, provided the
inspiration for the module. XML::Namespace essentially does the same thing,
albeit in a slightly different way. It's also available as a stand-alone
module for use in places unrelated to RDF.
The XML::NamespaceFactory module also implements similar functionality to
XML::Namespace, but instead uses the JClark notation (e.g.
"{
http://foo.org/ns/}title").