Accessing Metdata Fields

This page proves an overview of the API calls you can use to access the data in a DataObj. The example framing this is that of an export plugin.

The Plugin

Below is a very simple export plugin, which outputs a single eprint or list of eprints as Text citations.

package EPrints::Plugin::Export::Text;

use EPrints::Plugin::Export::TextFile;

@ISA = ( "EPrints::Plugin::Export::TextFile" );

use strict;

sub new
{
        my( $class, %opts ) = @_;

        my $self = $class->SUPER::new( %opts );

        $self->{name} = "ASCII Citation";
        $self->{accept} = [ 'dataobj/eprint', 'list/eprint' ];
        $self->{visible} = "all";

        return $self;
}


sub output_dataobj
{
        my( $plugin, $dataobj ) = @_;

        my $cite = $dataobj->render_citation;

        return EPrints::Utils::tree_to_utf8( $cite )."\n\n";
}

1;

Note the output_dataobj function. In an export plugin, this will be called on every item in the list that is being exported, and the results for all items aggregated and outputted.

There are two function calls of particular interest that aid in retrieving and managing data:

my $cite = $dataobj->render_citation;

This returns an HTML DOM object containing the citation of the dataobj as specified in the configuration files (see cfg/citations/eprint/default.xml). Given an HTML DOM object, the following call will convert it into a string:

my $text = EPrints::Utils::tree_to_utf8( $html_dom )