DublinCore::Record(3) Container for Dublin Core metadata elements

SYNOPSIS


use DublinCore::Record;

my $record = DublinCore::Record->new();

# later ...
# print the title
print $record->element( 'title' )->content;
## list context will retrieve all of a particular element
foreach my $element ( $record->element( 'Creator' ) ) {
print "creator: ", $element->content(), "\n";
}
## qualified dublin core
my $creation = $record->element( 'Date.created' )->content();

DESCRIPTION

DublinCore::Record is an abstract class for manipulating DublinCore metadata. The Dublin Core is a small set of metadata elements for describing information resources. For more information on embedding DublinCore in HTML see RFC 2731 <http://www.ietf.org/rfc/rfc2731> or <http://www.dublincore.org/documents/dces/>

METHODS

new()

The constructor. Takes no arguments. 

    $record = DublinCore::Record->new();

add( @elements )

Adds valid DublinCore::Element objects to the record.

remove( @elements )

Removes valid DublinCore::Element object from the record.

element()

This method will return a relevant DublinCore::Element object. When called in a scalar context element() will return the first relevant element found, and when called in a list context it will return all the relevant elements (since Dublin Core elements are repeatable). 

    ## retrieve first title element
    my $element = $record->element( 'Title' );
    my $title = $element->content();
    
    ## shorthand object chaining to extract element content
    my $title = $record->element( 'Title' )->content();
    
    ## retrieve all creator elements
    @creators = $record->element( 'Creator' );

You can also retrieve qualified elements in a similar fashion. 

    my $date = $record->element( 'Date.created' )->content();

In order to fascilitate chaining element() will return an empty DublinCore::Element object when the requested element does not exist. You can check if you're getting an empty empty back by using the is_empty() method. 

    if( $record->element( 'title' )->is_empty ) {
        # no title
    }

elements()

Returns all the Dublin Core elements found as DublinCore::Element objects which you can then manipulate further. 

    foreach my $element ( $record->elements() ) {
        print "name=", $element->name(), "\n";
        print "content=", $element->content(), "\n";
    }

title()

Returns a DublinCore::Element object for the title element. You can then retrieve content, qualifier, scheme, lang attributes like so. 

    my $title = $record->title();
    print "content:   ", $title->content(), "\n";
    print "qualifier: ", $title->qualifier(), "\n";
    print "scheme:    ", $title->scheme(), "\n";
    print "language:  ", $title->language(), "\n";

Since there can be multiple instances of a particular element type (title, creator, subject, etc) you can retrieve multiple title elements by calling title() in a list context. 

    my @titles = $record->title();
    foreach my $title ( @titles ) {
        print "title: ", $title->content(), "\n";
    }

creator()

Retrieve creator information in the same manner as title().

subject()

Retrieve subject information in the same manner as title().

description()

Retrieve description information in the same manner as title().

publisher()

Retrieve publisher information in the same manner as title().

contributor()

Retrieve contributor information in the same manner as title().

date()

Retrieve date information in the same manner as title().

type()

Retrieve type information in the same manner as title().

format()

Retrieve format information in the same manner as title().

identifier()

Retrieve identifier information in the same manner as title().

source()

Retrieve source information in the same manner as title().

language()

Retrieve language information in the same manner as title().

relation()

Retrieve relation information in the same manner as title().

coverage()

Retrieve coverage information in the same manner as title().

rights()

Retrieve rights information in the same manner as title().

AUTHOR

COPYRIGHT AND LICENSE

Copyright 2007 by Ed Summers, Brian Cassidy

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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