在Ruby on Rails的Restful身份验证中，＃self.included（base）是什么？(What does #self.included(base) do in Ruby on Ra

在Ruby on Rails的Restful身份验证中，＃self.included（base）是什么？(What does #self.included(base) do in Ruby on Rails' Restful Authentication?)

我以为我们会做

helper_method :current_user, :logged_in?, :authorized?

使这些控制器方法可用作视图中的辅助方法。 但是在Restful Authentication的lib/authenticated_system.rb ，我看到：

# Inclusion hook to make #current_user and #logged_in? # available as ActionView helper methods. def self.included(base) base.send :helper_method, :current_user, :logged_in?, :authorized? if base.respond_to? :helper_method end

为什么这样做而不是单行？ 另外，我看不到included被调用在任何地方。

I thought we would do

helper_method :current_user, :logged_in?, :authorized?

to make these controller methods available for use as helper methods in views. But in Restful Authentication's lib/authenticated_system.rb, I see:

# Inclusion hook to make #current_user and #logged_in? # available as ActionView helper methods. def self.included(base) base.send :helper_method, :current_user, :logged_in?, :authorized? if base.respond_to? :helper_method end

Why is it done this way instead of that single line? Also, I don't see included being called anywhere.

最满意答案

在包含模块时调用self.included函数。 它允许在基础（包括模块的位置）的上下文中执行方法。

更多信息： 一个ruby mixin教程 。

The self.included function is called when the module is included. It allows methods to be executed in the context of the base (where the module is included).

More info: a ruby mixin tutorial.