At present, derivative bitstreams created by filter-media all take on the authZ policies of their parent item. In some cases, such as locked images, the thumbnail could still be open.
From a recent thread on dspace-tech. It seems as if this would make a useful feature if we can agree on a set of requirements:
Thanks for your reply. Do you have open access to any of your content or is it all restricted? We have a mix which makes running the filter-media etc scripts interesting.
Ideally the solution would be to set permissions at a collection level for each of the types of bundles. The item permissions would then inherit from the collection, or override if policies are set on individual items.. I don't seem to be able to do that (1.5).
For reference, heres the (cutdown) SQL. This will update all thumbnail bitstream policies and set them to anonymous. We only had to do it for one group though. If you want to update intermediates, change THUMBNAIL to BRANDED_PREVIEW.
where policy_id in (
On 04/11/2010, at 11:59 PM, George Stanley Kozak wrote:
This is the way that thumbnails have worked for me at my site (we have been using DSpace since 2003). It can be frustrating. Your solution is interesting. I never thought about going into SQL to update the policies on the thumbnail bundles. I am not sure if there are any other solutions.
Digital Library Specialist
Cornell University Library Information Technologies (CUL-IT)
501 Olin Library
Ithaca, NY 14853
From: Steve Swinsburg email@example.com
Sent: Wednesday, November 03, 2010 9:39 PM
Subject: Re: [Dspace-tech] thumbnails restricted if main item is restricted
We've fixed this up with some carefully crafted SQL to update the policies to the Anonymous group for the bitstreams in the thumbnail bundles, but it would be interesting to know if this is actually how things are meant to work, ie inherit the permissions from the parent item when generating the thumbnails.
On 04/11/2010, at 10:53 AM, Steve Swinsburg wrote:
We have a situation where some items in a collection are restricted, ie you need to login to access the full version. However we want the thumbnails and branded previews to still show up for the general public.
When we run the thumbnail generator, it seems to inherit the permissions from the main bitstream, which means if the bitstream is protected, the thumbnail doesn't show up unless you are logged in and have the appropriate permission.
Is this a common situation? We've inherited this instance so it might be a change made by people before us, but if anyone has addressed this, it would be great to hear from you.