How can I resize a Paperclip image after it has been added to the database?

Question

I've added 2000 pictures to my images table and I'm using the Paperclip plugin to create thumbs. I'm wondering if there's a way to go through the database and add another :styles element.

For example, when I added the images I had the following in my model:

has_attached_file :image, :styles => { :medium => "300x300>", :thumb => "100x100>" }

However, now I want to add a :large attribute and have it applied to every image that's already in my table. Something like:

has_attached_file :image, :styles => { :large => "800x800>", :medium => "300x300>", :thumb => "100x100>" }

Is this possible? Or would I have to re-add all 2000 pictures?

Answer 1

rake paperclip:refresh:thumbnails

Answer 2

I'm also having problems with this. I get:

$: rake paperclip:refresh:thumbnails RAILS_ENV=production CLASS=Photo
(in /home/public_html/XXXXX/releases/20091108211450)
rake aborted!
undefined method `read' for nil:NilClass
/usr/lib/ruby/gems/1.8/gems/paperclip-2.1.2/lib/paperclip/attachment.rb:163:in `reprocess!'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:45
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:26:in `for_all_attachments'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:24:in `each'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:24:in `for_all_attachments'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:22:in `each'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:22:in `for_all_attachments'
/home/avishai/public_html/XXXXX/releases/20091108211450/lib/tasks/paperclip.rake:44

Does anyone know what's going on?

Thanks!

Answer 3

If Paperclip is installed as a plugin, you can do this:

rake paperclip:refresh:thumbnails CLASS=Screenshot

where Screenshot is the name of the class with the attachment.

If it's installed as a gem, do this inside script/console:

Screenshot.all.each {|s| s.image.reprocess! }

replacing Screenshot with the appropriate class name