Editing DataCite DOI (section)

=Document Landing Pages=
The DataCite DOI plugin supports minting DOIs for documents uploaded to eprint records, however all DOIs must resolve to a landing page however and so in order to enable this your repository needs to support document landing pages. The following code snippets illustrate how to implement document landing pages in EPrints.

First we need a URL rewrite trigger to catch the URLs which should resolve to the landing page. The following needs to be added to the eprints or archives' configuration files, e.g. '''lib/cfg.d/doc_landing_pages.pl'''. We can also define a flag here for plugins to check to see if document landing pages are enabled on this repository.

<pre>
# configuration flag used to check if document landing pages are enabled on this repository
$c->{doc_landing_pages_enabled} = 1;

$c->add_trigger( EP_TRIGGER_URL_REWRITE, sub
{
    my( %args ) = @_;

    my( $uri, $rc, $request ) = @args{ qw( uri return_code request ) };

    # matches https://myrepo.ac.uk/document/<doc_id>
    if( defined $uri && ($uri =~ m#^/document/(.*)$# ) )
    {
        $request->handler('perl-script');
        $request->set_handlers(PerlResponseHandler => [ 'EPrints::Apache::Document' ] );
        ${$rc} = EPrints::Const::OK;
    }

    return EP_TRIGGER_OK;

}, priority => 100 );
</pre>

This trigger uses a Document handler we need to implement, e.g. '''perl_lib/EPrints/Apache/Document.pm'''

<pre>
######################################################################
#
# EPrints::Apache::Document
#
######################################################################

package EPrints::Apache::Document;

use strict;

use EPrints;
use EPrints::Apache::AnApache;

sub handler
{
    my( $r ) = @_;

    my $uri = $r->uri;

    if( $uri =~ m#^/document/(.*)$# )
    {
        my $repository = $EPrints::HANDLE->current_repository;
        return DECLINED if( !defined $repository );

        # Document landing pages enabled for this repository?
        return DECLINED unless( $repository->config( "doc_landing_pages_enabled" ) );

        my $doc_id = $1;

        my $doc_ds = $repository->dataset( "document" );
        my $doc = $doc_ds->dataobj( $doc_id );

        if( defined $doc )
        {
            EPrints::ScreenProcessor->process(
                session => $repository,
                screenid => "Document",
                document => $doc,
            );
            return OK;
        }
    }

    return DECLINED;
}

1;
</pre>

The handler calls on an EPrints screen to generate the content for the landing page, e.g. '''perl_lib/EPrints/Plugin/Screen/Document.pm'''

<pre>
=head1 NAME

EPrints::Plugin::Screen::Document

=cut#

package EPrints::Plugin::Screen::Document;

use EPrints::Plugin::Screen;

@ISA = ( 'EPrints::Plugin::Screen' );

use strict;

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

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

    return $self;
}

sub properties_from
{
    my( $self ) = @_;

    $self->{processor}->{eprint} = $self->{processor}->{document}->get_eprint;

    $self->SUPER::properties_from;
}

sub render_title
{
    my( $self ) = @_;

    my $session = $self->{session};

    my $f = $self->{session}->make_doc_fragment;

    my $eprint = $self->{processor}->{eprint};
    my $doc = $self->{processor}->{document};

    $f->appendChild( $self->{processor}->{eprint}->render_citation( "screen" ) );

    $f->appendChild( $self->{session}->html_phrase( "document_join" ) );

    $f->appendChild( $self->{processor}->{document}->render_citation( "screen" ) );

    return $f;
}

sub render
{
    my( $self ) = @_;

    my $repo = $self->{repository};
    my $doc =  $self->{processor}->{document};

    my $page = $repo->make_doc_fragment;

    my $div = $repo->make_element( "div", class => "doc_citation" );

    $div->appendChild( $doc->render_citation( "landing_page", eprint => $self->{processor}->{eprint} ) );

    return( $div );
}

1;
</pre>

And finally, the screen uses a citation file to display the document landing page content in an easily customisable fashion, e.g. '''lib/defaultcfg/citations/document/landing_page.xml'''

<pre>

<?xml version="1.0" ?>

<!--
    Full "abstract page" (or splash page or summary page, depending on your jargon) for an eprint.
-->

<cite:citation xmlns="http://www.w3.org/1999/xhtml" xmlns:epc="http://eprints.org/ep3/control" xmlns:cite="http://eprints.org/ep3/citation" >

    <!-- Display the parent eprint citation -->
    <epc:print expr="$eprint.citation_link('default')" />

    <!-- Display the document details in a similar fashion to eprint summary pages -->
    <table>
        <tr>
            <td valign="top" align="right"><epc:print expr="$item.icon( 'HoverPreview', 'noNewWindow' )" /></td>
            <td valign="top">
                <epc:print expr="$item.citation('default')" /><br />
                <a href="{$item.url()}" class="ep_document_link"><epc:phrase ref="summary_page:download"/> (<epc:print expr="$item.doc_size().human_filesize()" />)</a>
            </td>
          </tr>
      </table>

</cite:citation>
</pre>