DVGM/app/controllers/application_controller.rb

class ApplicationController < ActionController::Base
  helper_method :current_user, :logged_in_as_student, :logged_in_as_lecturer,
    :logged_in_as_admin, :kick_out

private
  def kick_out
    raise ActionController::RoutingError.new('Not Found')
  end

  def logged_in_as_student
    return (current_user and current_user.role == "student")
  end

  def logged_in_as_lecturer
    return (current_user and current_user.role == "lecturer")
  end

  def logged_in_as_admin
    return (current_user and current_user.role == "admin")
  end

  def current_user
    return @current_user if defined?(@current_user)
    @current_user = User.where("session = '#{cookies[:session]}' and session not NULL").first
  end
  
  def store_location
    session[:return_to] = request.original_url
  end
  
  def redirect_back_or_default(default)
    redirect_to(session[:return_to] || default)
    session[:return_to] = nil
  end
end