## applicaton_controller.rb
class ApplicationController < ActionController::Base
  helper :all # include all helpers, all the time
  protect_from_forgery # See ActionController::RequestForgeryProtection for details
	filter_parameter_logging :password, :password_confirmation

	helper_method :require_user

	private
	def current_user_session
		return @current_user_session if defined?(@current_user_session)
		@current_user_session = UserSession.find
	end

	def current_user
		return @current_user if defined?(@current_user)
		@current_user = current_user_session && current_user_session.record
	end

	def require_user
		unless current_user
			store_location
			flash[:notice] = "You must be logged in to access this page"
			redirect_to root_url
			return false
		end
	end

	def require_no_user
		if current_user
			store_location
			flash[:notice] = "You must be logged out to access this page"
			redirect_to root_url
			return false
		end
	end

	def store_location
		session[:return_to] = request.request_uri
	end

	def redirect_back_or_default(default)
		redirect_to(session[:return_to] || default)
		session[:return_to] = nil
	end
end

##election_dates_controller.rb
class ElectionDatesController < ApplicationController
	before_filter require_user, :only => [ :edit, :update, :new, :create ]

	def index
		@election_pages = ElectionDate.find(:all)
	end
end


## the result:
undefined local variable or method `require_user' for ElectionDatesController:Class