alter :path_prefix boldly job has_attachment around tie fu plugin

by default stores uploaded files "public/#{table_name}". i wish cgange something "public/#{table_name}/#{site_id}", where site_id ability model. note i've attempted controlling self.site_id both fail.

has_attachment :storage => :file_system, 
               :max_size => 25.megabytes,
               :path_prefix => "public/#{table_name}/#{site_id}",
               :thumbnails => { 
                 :large => '256x256>', 
                 :medium => '128x128>', 
                 :small => '64x64>' 
               }

i accept "undefined internal non-static slight site_id" blunder messages. stealing #{site_id} member :path_prefix works glorious initialize slight run. i opening site_id expected.

i have an initialize slight looks this:

def initialize(site_id = nil)
  super(nil)
  self.site_id ||= site_id
end

i instanciate vigilant around rails console this:

r = resource.new(100)

is has_attachment slight controlling before initialize method? i pass parameter :path_prefix boldly denote instantiated?