Mengakses session dari model

class ActionController::Base
  before_filter :set_session
 
  def self.session_on
    ActiveRecord::Base.class_eval <<-END_EVAL
      @@my_session = nil
     
      def self.my_session=(val)
        @@my_session = val
      end
     
      def self.my_session
        @@my_session
      end  
     
      def my_session
        @@my_session
      end
    END_EVAL
   
  end 
  session_on
 
  def set_session
    ActiveRecord::Base.my_session = session
  end
end