gistfile1.rbx

Paperclip::Attachment.interpolations[:hashed_id_3x3] = lambda do |attachment, style|
  hash = Digest::MD5.hexdigest(attachment.instance.id.to_s)
  hash_path = ''
  3.times { hash_path += '/' + hash.slice!(0..2) }
  hash_path(1..12)
end

Paperclip::Attachment.interpolations[:hashed_id] = lambda do |attachment, style|
  Digest::MD5.hexdigest(attachment.instance.id.to_s)
end

Paperclip::Attachment.interpolations[:kind] = lambda do |attachment, style|
  attachment.instance.kind
end

Paperclip::Attachment.interpolations[:format] = lambda do |attachment, style|
  attachment.instance.format
end