A small Ruby module which provides access to the current controller everywhere you could need it. Works in multithreaded environments.

current_controller.rb

module CurrentController
  def self.included(base)
    base.before_filter :set_current_controller
  end

  def set_current_controller
    Thread.current[:current_controller] = self
  end
end

def current_controller
  Thread.current[:current_controller]
end

# Setup it up
# ActionController::Base.send :include, CurrentController