[EP-tech] Adding new Data Objects into EPrints 3.2

[Ian Stuart]

I've looked at the documentation and the training material, and I think 
I understand how it works:

I create EPrints::DataObj::Foo packages in 
~~eprints/archives/<ARCHIVE_ID>/cfg/plugins/EPrints/DataObj/

I enable them in 
~~eprints/archives/<ARCHIVE_ID>/cfg/cfg.d/zz_postcards.pl thus:

----- code ------
use strict;
use warnings;

if( !defined $c->{datasets} )
{
	$c->{datasets} = {};
}

$c->{datasets}->{postcard} = {
     class => 'EPrints::DataObj::Subscriber',
   sqlname => 'subscriber',
};
$c->{datasets}->{subscriber} = {
   class    => 'EPrints::DataObj::Postcard',
   sqlname => 'postcard',
};
$c->{datasets}->{subscriberticket} = {
   class   => 'EPrints::DataObj::SubscriberTicket',
   sqlname => 'subscriberticket',
};
----- code ------
(copied from datasets.pl)

I have checked all three packages: all three are well formed (they can 
be reformatted with perltidy), and reasonable sound (there are minor 
warnings from perlcritic)

The problem is my server will now not start:
[Tue Dec 17 15:37:24 2013] [error] Can't locate object method 
"get_system_field_info" via package "EPrints::DataObj::Subscriber" 
(perhaps you forgot to load "EPrints::DataObj::Subscriber"?) at 
/home/broker/eprints/perl_lib/EPrints/DataSet.pm line 407.\n

If I move them into ~~/eprints/perl_lib/EPrints/DataObj/ and restart the 
server, I still don't see them

The problem appears to be in zz_postcards.pl - if I dump the contents of 
$c->{datasets} in zz_postcards.pl then I only see my three packages, 
which is NOT what I'd expect to see.

Any ideas as to why the packages are not being loaded, and how to kick 
them into life?

-- 

Ian Stuart.
Developer: ORI, RJ-Broker, and OpenDepot.org
Bibliographics and Multimedia Service Delivery team,
EDINA,
The University of Edinburgh.

http://edina.ac.uk/

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