将模块方法调用到Ruby中的另一个模块中

FIle module.rb

文件module.rb

module CardExpiry
  def check_expiry value
    return true
  end
end

file include.rb

文件include.rb

#raise File.dirname(__FILE__).inspect
require "#{File.dirname(__FILE__)}/module.rb"

 module Include
     include CardExpiry
  def self.function 
    raise (check_expiry 1203).inspect
  end
end

calling

调用

Include::function

is this possible ?

这是可能的吗?

Error trigger when calling :

调用时错误触发:

`function': undefined method `check_expiry' for Include:Module (NoMethodError)

2 个解决方案

#1

You stumbled over the difference of include and extend.

你在包含和扩展的差异上犯了错误。

include makes the method in the included module available to instances of your class
包括使包含的模块中的方法可用于类的实例。
extend makes the methods in the included module available in the class
扩展使所包含模块中的方法在类中可用

When defining a method with self.method_name and you access self within that method, self is bound to the current class.

用self定义方法时。method_name和您在该方法中访问self, self被绑定到当前类。

check_expiry, however, is included and thus only available on the instance side.

但是，包含check_expire，因此只能在实例端可用。

To fix the problem either extend CardExpiry, or make check_expiry a class method.

要解决这个问题，可以扩展CardExpiry，或者将check_expiration设置为类方法。

#2

I've looked at your problem in a bit more detail, and the issue is your module.rb file:

我已经详细地研究了您的问题，问题是您的模块。rb文件:

module CardExpiry
  def self.check_expiry value
    return true
  end
end

First, there was an end missing from the file - both def and module need to be closed.

首先，文件中缺少一个结束——def和模块都需要关闭。

Second, the magical self. in the def line turns the method into a pseudo-global function - this answer explains it better than I can.

第二,神奇的自我。在def行中，将方法转换为伪全局函数——这个答案比我能更好地解释它。

Furthermore, to call the method, you need to use:

此外，要调用该方法，需要使用:

raise (CardExpiry::check_expiry 1203).inspect

#1