Cookie已签名 - 未定义方法'已签名'

Question

在Application Controller中，如果cookies.signed [：user_id]，我有一个方法current_user和if语句。该方法一直有效，但今天我创建了新的控制器和路由，它给我一个错误

undefined method `signed' for nil:NilClass

这是应用程序控制器：

class ApplicationController < ActionController::Base
  protect_from_forgery with: :null_session

  before_action :current_user

  protected
  def current_user
    if cookies.signed[:user_id] && User.find(cookies.signed[:user_id])
      @current_user = User.find(cookies.signed[:user_id])
    end
  end
end

这是服务器日志：

Processing by HomeController#index as HTML
Completed 500 Internal Server Error in 23ms (ActiveRecord: 0.0ms) 

NoMethodError (undefined method `signed' for nil:NilClass):

app/controllers/application_controller.rb:18:in `current_user'
  Rendering /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout
  Rendering /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_source.html.erb
  Rendered /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (4.5ms)
  Rendering /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
  Rendered /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.0ms)
  Rendering /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb
  Rendered /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.3ms)
  Rendered /Users/Dudis/.rvm/gems/ruby-2.3.1/gems/actionpack-5.0.6/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (187.4ms)

任何建议为什么它不再起作用？我没有在应用程序中进行任何更新。

Answer 1

从错误中可以看出，方法cookies返回nil。即使你没有任何cookie，AFAIK，rails的实现也不应该这样做。这让我觉得它不是正在运行的rails版本。如果我猜测，你在该控制器中有一个方法cookies（在评论中确认）。

Answer 2

cookies是零undefined method signed for nil:NilClass (nil.signed)