过滤器出现之前的顺序是什么？ [英] What order do before filters occur in?

问题描述

过滤器出现之前的顺序是什么？具体来说，关于inheiritance，before_action过滤器出现了什么顺序？例如，这是否有效：

What order do before filters occur in? Specifically, what order do the before_action filters occur in, in regards to inheiritance? For example, will this work:

class A < ActionController::Base
  before_action :set_user

  def set_user
    @user = something
  end
end

class B < A
  before_action :set_post

  def show
    render @post
  end

  def set_post
    @post = @user.posts.first
  end
end

B＃show会工作吗？筛选顺序有哪些规则供将来参考？我在Rails文档中找不到任何这个。

Will "B#show" work? What are the rules for filter order for future reference? I can't find any of this in the Rails documentation.

推荐答案

我建议看一下 源代码 和<过滤器上的strong> API文档 。

I suggest taking a look at the source code and API Docs on filters.

默认订购应为

1. ：set_post


2. ：set_user

1. :set_post
2. :set_user

我认为如果您想将：set_user 推到堆栈顶部，您可以更改 A 到

I think if you wanted to push :set_user to the top of the stack you could change the line in A to

prepend_before_action :set_user

另外值得指出的是，这不是关于该主题的唯一问题;这里有其他人 。

Also worth pointing out, this isn't the only question on the topic; there are others here on SO.

至于您的具体情况，您似乎需要更改 A 正如我上面提到的那样，为了 @user 在 set_post 中分配 B 运行。

As for your specific situation, it looks like you'll need to change A as I mentioned above in order to have @user be assigned by the time set_post in B runs.

自4.2.6起（可能已更改）在早期版本中，订购现在是孩子之前的父母：

As of 4.2.6 (probably changed in an earlier version), the ordering is now parent before child:

1. ：set_user


2. ：set_post

1. :set_user
2. :set_post

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