thoughtbot/paperclip — pull request #1014 by Tei (2012-09-10 06:35:56+00:00)
Title: allow to use lambdas in only_process option

We can use lambdas in styles option. And can use different styles for different objects. But I want to process only 1 thumbnail immediately for every object, and styles for this thumb can be different for different objects. All other thumbs will be processed with 'reprocess!' command in background.