From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-11-19T19:12:03+09:00
Subject: Re: Is there a way to know what are the subclasses of a given class ?

> On 2008.11.19., at 10:10, Sandro Paganotti wrote:
>
>> [SOLVED]
>>
>> I just find out that you can call:
>>
>> A.constants --> ["B","C"]
>>
>> Thank you
>>
>> Sandro
>>
>> On Wed, Nov 19, 2008 at 10:10 AM, Sandro Paganotti <
>> sandro.paganotti@gmail.com> wrote:
>>
>>> Hello
>>>
>>> Do you know if there's a trick to retrieve a list of all the subclasses
>>> of
>>> a given class ?
>>>
>>> class A
>>>  class B
>>>  end
>>>  class C
>>>  end
>>> end
>>>
>>> like  A.subclasses  --> [B,C] ?

As has been mentioned, in your example B and C are not subclasses of A.
If you want to list all subclasses of a class you can do this:

irb(main):001:0> class A
irb(main):002:1> class << self
irb(main):003:2> attr_accessor :subclasses
irb(main):004:2> end
irb(main):005:1> def self.inherited child
irb(main):006:2> (A.subclasses ||= []) << child
irb(main):007:2> end
irb(main):008:1> end
=> nil
irb(main):009:0> A.subclasses
=> nil
irb(main):010:0> class B < A; end;
irb(main):011:0* A.subclasses
=> [B]
irb(main):012:0> class C < B; end;
irb(main):013:0* A.subclasses
=> [B, C]
irb(main):014:0> class D < A; end;
irb(main):015:0* A.subclasses
=> [B, C, D]

Hope this helps,

Jesus.