View source for How to make a Screen for the Admin Section

[[Category:Howto]]
[[Category:Plugins]]
[[Category:User Roles]]
 Known to work for EPrints 3.2+ 

== The basic structure ==
To make a Screen plugin, you create a Perl Module in <code>[eprints]/archives/<ARCHIVE_ID>/cfg/plugins/EPrints/Plugin/Screen/</code> with the following basic structure
<pre>

package EPrints::Plugin::Screen::Mypackage;

use EPrints::Plugin::Screen;

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

use strict;

sub new
{
	my( $class, %params ) = @_;
	my $self = $class->SUPER::new(%params);
	$self->{priv} = undef;
	$self->{appears} = [
		{ 
			place => "admin_actions_editorial", # see notes below
			position => 1450, 
		},
	];
	return $self;
}

sub can_be_viewed
{
	my( $self ) = @_;
	return $self->allow( "my/conf/value" );
}

sub render
{
	my( $self ) = @_;
	my $session = $self->{session};
        my $user = $session->current_user;

        my $p = $session->make_doc_fragment;

        # create page contents:
        my $h = $session->make_element( "h3" );
        $h->appendChild($session->make_text( "Look up organisations known to OA-RJ" ));
        $p->appendChild($h);

	return $p
}
</pre>

In theory, one should be able to have multiple bits of functionality (view a little, view a lot, edit, etc), simply by testing for different values of <code>$self->allow( "my/conf/value" )</code>

== The locations ==
Where the link for the page appears is defined by <code>$self->{appears}->[''n'']->{place}</code> (in the <code>new</code> function.)

We are defining a screen that appears in the "admin" area, and there are 4 tabs defined within the admin screen:
* admin_actions_editorial
* admin_actions_system
* admin_actions_config
* admin_actions_misc

Other places the link can appear are
* unknown to me

== Making the page appear ==
There are three steps to making a page appear:

1. The screen plugin should test for ''view-ability''
<pre>
# in EPrints::Plugin::Screen::Mypackage
sub can_be_viewed
{
	my( $self ) = @_;
	return $self->allow( "my/conf/value" );
}
</pre>
2 The ''User'' DataObject needs to list the privilege under a role:
<pre>
  # In EPrints::DataObj::User
  foo_bar => [
    "my/view/value",
  ],
  foo_baz => [
    "my/view/value",
    "my/conf/value",
  ],
</pre>
3 The user_roles.pl file needs to make the role available to the user-type:
<pre>
# in [eprints]/archive/<ARCHIVE_ID>/cfg/cfg/user_roles.pl
$c->{user_roles}->{user} = [qw{
	// truncated
	foo_bar
}],
$c->{user_roles}->{admin} = [qw{
        // truncated
	foo_baz
}],
</pre>

Return to the main [[Screen_Plugins]] page.

== See Also ==
* [[Listings of User Roles and Privileges]] - A reference to role and privileges and what they allow a user to do.
* [[User_roles.pl|user_roles.pl]] - Describe the configuration file and how it may be edited/extended to modify/add new roles and privileges.