How to Intercept Class Definitions in Ruby?

Question

Is it possible to code something that can tell me when a Ruby class is defined?

Could you please tell us what you actually want from us? – Arup Rakshit Feb 23 '13 at 15:37 — Arup Rakshit, Feb 23 '13 at 15:37

Russell · Answer 1 · 2013-02-26T07:47:39.003

Yes!

class Object  
  def self.inherited(base)
    puts "#{base} inherited from object"
  end
end

class Animal
end

class Cat < Animal
end

Running the above code prints the following:

Animal inherited from object
Cat inherited from object

Basically, the self.inherited callback is triggered whenever a class is defined that inherits from the class it is defined on. Put it on Object and that's any class! (Although there may be some special case exceptions I can't think of just now).

I should probably add the disclaimer that, while it is possible to do this (because of just how awesome Ruby is as a language), whether it is advisable to do this, especially in code destined for production use, I'm not so sure. Well, actually, I am sure. It would be a bad idea.

Edit your top comment into your answer. – Linuxios Feb 26 '13 at 02:38 — Linuxios, Feb 26 '13 at 02:38

How to Intercept Class Definitions in Ruby?

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