Editing Building a DataSet (section)

==Modify EPrint Status Field==

Since our dark archive will contain eprints we will be making a new virtual dataset. A virtual dataset is a sub set of an existing dataset. Values of metadata fields on an object can be used to determine which virtual datasets it is in. The inbox, archive and buffer are all virtual datasets of the eprint dataset. The field which defines these virtual datasets is the "eprint_status" field. We must modify this field so it has an extra value "dark_archive". To do this add the following code to the postins method of your plugin configuation file from the workflow excercise. (Note you should not add the coresponding remove_dataset_field)

<pre>
 $repository->config->add_dataset_field( "eprint", {
  name=>"eprint_status", type=>"set", required=>1,
  options=>[qw/ inbox buffer archive deletion dark_archive /],
  replace_core=>1 #this flag must be used with EXTREME caution, it makes is very easy to break things
}, reuse => 1 );

</pre>