NAME
RDF::NS - Just use popular RDF namespace prefixes from prefix.cc
VERSION
version 20111031
SYNOPSIS
use RDF::NS '20111031'; # check at compile time
my $ns = RDF::NS->new('20111031'); # check at runtime
$ns->foaf; # http://xmlns.com/foaf/0.1/
$ns->foaf_Person; # http://xmlns.com/foaf/0.1/Person
$ns->foaf('Person'); # http://xmlns.com/foaf/0.1/Person
$ns->URI('foaf:Person'); # http://xmlns.com/foaf/0.1/Person
$ns->SPAQRL('foaf'); # PREFIX foaf: <http://xmlns.com/foaf/0.1/>
$ns->TTL('foaf'); # @prefix foaf: <http://xmlns.com/foaf/0.1/> .
$ns->XMLNS('foaf'); # xmlns:foaf="http://xmlns.com/foaf/0.1/"
# To get RDF::Trine::Node::Resource instead of strings
use RDF::NS::Trine;
$ns = RDF::NS::Trine->new('20111031');
$ns->foaf_Person; # iri('http://xmlns.com/foaf/0.1/Person')
# load your own mapping
$ns = RDF::NS::LOAD("mapping.txt");
# select particular mappings
%map = $ns->SELECT('rdf,dc,foaf');
$uri = $ns->SELECT('foo|bar|doz'); # returns first existing namespace
# instances are just blessed hash references
$ns->{'foaf'}; # http://xmlns.com/foaf/0.1/
bless { foaf => 'http://xmlns.com/foaf/0.1/' }, 'RDF::NS';
print (scalar %$ns) . "prefixes\n";DESCRIPTION
Hardcoding URI namespaces and prefixes for RDF applications is neither fun nor maintainable. In the end we all use more or less the same prefix definitions, as collected at http://prefix.cc. This module includes all these prefixes as defined at specific snapshots in time. These snapshots correspond to version numbers of this module. By selecting particular versions, you make sure that changes at prefix.cc won't affect your scripts.
This module does not require RDF::Trine which is recommended nevertheless. If you prefer RDF::NS to return instances of RDF::Trine::Node::Resource instead of plain strings, use RDF::NS::Trine.
The code repository of this module contains an update script to download the current prefix-namespace mappings from http://prefix.cc.
METHODS
new ( $version [, %options ] )
Create a new namespace mapping with a selected version (mandatory). The special version string "any" can be used to get the newest mapping - actually this is $RDF::NS::VERSION, but you should better select a specific version, as mappings can change, violating backwards compatibility. Supported options include warn to enable warnings.
LOAD ( $file [, %options ] )
Load namespace mappings from a particular tab-separated file. See NEW for supported options.
URI ( $short )
Expand a prefixed URI, such as foaf:Person. Alternatively you can expand prefixed URIs with method calls, such as $ns->foaf_Person.
TTL ( prefix[es] )
Returns a Turtle/Notation3 @prefix definition or a list of such definitions in list context. Prefixes can be passed as single arguments or separated by commas, vertical bars, and spaces.
SPARQL ( prefix[es] )
Returns a SPARQL PREFIX definition or a list of such definitions in list context. Prefixes can be passed as single arguments or separated by commas, vertical bars, and spaces.
XMLNS ( prefix[es] )
Returns an XML namespace declaration or a list of such declarations in list context. Prefixes can be passed as single arguments or separated by commas, vertical bars, and spaces.
SELECT ( prefix[es] )
In list context, returns a sorted list of prefix-namespace pairs, which can be used to assign to a hash. In scalar context, returns the namespace of the first prefix that was found. Prefixes can be passed as single arguments or separated by commas, vertical bars, and spaces.
MAP ( $code [, prefix[es] ] )
Internally used to map particular or all prefixes. Prefixes can be selected as single arguments or separated by commas, vertical bars, and spaces. In scalar context, $_ is set to the first existing prefix (if found) and $code is called. In list context, found prefixes are sorted at mapped with $code.
GET ( $uri )
This method is used internally to create URIs as return value of the URI method and all lowercase shortcut methods, such as foaf_Person. By default it just returns $uri unmodified.
SEE ALSO
There are several other CPAN modules to deal with IRI namespaces, for instance RDF::Trine::Namespace, RDF::Trine::NamespaceMap, RDF::Prefixes, RDF::Simple::NS, RDF::RDFa::Parser::Profile::PrefixCC etc.
AUTHOR
Jakob Voss
COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Jakob Voss.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.