rails 记住跳转前的url

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

    # Redirect to the URI stored by the most recent store_location call or
    # to the passed default.
    def redirect_back_or_default(default)
      redirect_to(session[:return_to] || default)
      session[:return_to] = nil
    end