RDF::Prefixes - simple way to turn URIs into QNames
my $context = RDF::Prefixes->new; say $context->qname('http://purl.org/dc/terms/title'); # dc:title say $context->qname('http://example.net/rdf/dc#title'); # dc2:title say $context->turtle; # @prefix dc: <http://purl.org/dc/terms/> . # @prefix dc2: <http://example.net/rdf/dc#> .
This module is not so much for managing namespaces/prefixes in code (see RDF::Trine::NamespaceMap for that), but as a helper for code that serialises data using namespaces.
It generates pretty prefixes, reducing "http://purl.org/dc/terms/" to "dc" rather than something too generic like like "ns01", and provides a context for keeping track of namespaces already used, so that when "http://purl.org/dc/elements/1.1/" is encountered, it won't stomp on the previous definition of "dc".
new(\%suggestions, \%options)
Creates a new RDF prefix context.
Suggestions for prefix mappings may be given, but there's no guarantee that they'll be used.
The only option right now is 'syntax' that is used by the to_string method.
Both hashrefs are optional.
get_prefix($uri)
Gets the prefix associated with a URI. e.g. get_prefix('http://purl.org/dc/terms/') might return 'dc'.
get_prefix('http://purl.org/dc/terms/')
get_qname($uri)
Gets a QName for a URI. e.g. get_qname('http://purl.org/dc/terms/title') might return 'dc:title'.
get_qname('http://purl.org/dc/terms/title')
Some URIs cannot be converted to QNames. In these cases, undef is returned.
get_curie($uri)
As per get_qname, but allows for more relaxed return values, suitable for RDFa, Turtle or Notation 3, but not RDF/XML. Should never need to return undef.
get_qname
preview_prefix($uri)
preview_qname($uri)
preview_curie($uri)
As per the "get" versions of these methods, but doesn't modify the context.
to_hashref
Returns a hashref of prefix mappings used so far. This is not especially necessary as the object may be treated as a hashref directly:
foreach my $prefix (keys %$context) { printf("%s => %s\n", $prefix, $context->{$prefix}); }
TO_JSON
A synonym for to_hashref, provided for the benefit of the JSON package.
rdfa
Return the same data as to_hashref, but as a string suitable for placing in an RDFa 1.1 prefix attribute.
sparql
Return the same data as to_hashref, but as a string suitable for prefixing a SPARQL query.
turtle
Return the same data as to_hashref, but as a string suitable for prefixing a Turtle or Notation 3 file.
xmlns
Return the same data as to_hashref, but as a string of xmlns attributes, suitable for use with RDF/XML or RDFa.
to_string
Calls either rdfa, sparql, turtle (the default) or xmlns, based on the 'syntax' option passed to the constructor. This module overloads the stringification operator, so explicitly calling to_string is rarely necessary.
my $context = RDF::Prefixes->new({}, {syntax=>'turtle'}); my $dc_title = 'http://purl.org/dc/terms/title'; print "# Prefixes\n" . $context;
Strings passed to and from this module are expected to be utf8 character strings, not byte strings. This is not explicitly checked for, but will be checked in a future version, so be warned!
URIs containing non-Latin characters should "just work".
Please report any bugs to http://rt.cpan.org/.
Toby Inkster <tobyink@cpan.org>.
Copyright 2010-2013 Toby Inkster
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
To install RDF::Prefixes, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RDF::Prefixes
CPAN shell
perl -MCPAN -e shell install RDF::Prefixes
For more information on module installation, please visit the detailed CPAN module installation guide.