我覆盖了 devise session 的 create 方法，判断当用户被禁用时，无法登录，我的代码如下：

def create
   resource = warden.authenticate!(:scope => resource_name, :recall => "#{controller_path}#new")
   if resource.is_deleted?
     render :new
  else
     sign_in(resource_name, resource)
     redirect_to after_sign_in_path_for(resource)
   end
 end

但是感觉不对，我看了一下 ruby-china 的代码如下：但是我没看到是如何处理的，谁帮忙解释一下

def create
    resource = warden.authenticate!(:scope => resource_name, :recall => "#{controller_path}#new")
    set_flash_message(:notice, :signed_in) if is_navigational_format?
    sign_in(resource_name, resource)
    resource.ensure_private_token!
    respond_to do |format|
      format.html { redirect_to after_sign_in_path_for(resource) }
      format.json { render :status => '201', :json => resource.as_json(:only => [:login, :email, :private_token]) }
    end
  end