Rails redirection

app_controller.rb

class AdminController < ApplicationController
  
  # Execute the filter to authenticate users (::authenticate)
  before_filter :authenticate
  
  def user
  end

  def unit
  end

  def index
  end

end

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  
  # Execute the filter to select logged in user
  before_filter :fetch_logged_user
  
  # Find the logged in user in DB to verify
  def fetch_logged_user
    unless session[:user_id].blank?
      # Find the user by stored session ID
      @logged_user  = User.find( session[:user_id] )
    end
    
  # rescue ActiveRecord::RecordNotFound
  end
  
  # Filter employed to perform actual authentication
  def authenticate
    # Check if the login user is set
    unless @logged_user
      redirect_to login_path, :status => 401                       # Redirect to the login form
      flash[:msg] = 'You must be logged in to access this page';  # Set a flash message
      return false
    end
  end
  
end