From: Heesob Park <phasis@...>
Date: 2008-08-18T10:57:07+09:00
Subject: Re: Where did this constant come from?

Hi,

2008/8/18 David Masover <ninja@slaphack.com>:
> What's the simplest way to find out where a constant was defined?
>
> I did come up with a way (probably partly ripped off from ActiveSupport), but
> it feels convoluted and fragile:
>
>
> class Module
>  def parent_namespace
>    parts = self.name.split('::')
>    if parts.length > 1
>      parts.tap(&:pop).join('::').constantize
>    else
>      nil
>    end
>  end
>
>  def eldest_ancestor_with_const name
>    if const_defined? name
>      klass = self
>      self.ancestors.each do |ancestor|
>        break if klass == Object
>        break unless ancestor.const_defined? name
>        klass = ancestor
>      end
>      klass
>    else
>      nil
>    end
>  end
>
>  def find_const_parent name
>    if Object.const_defined? name
>      Object
>    else
>      klass = self
>      until klass.const_defined? name
>        klass = klass.parent_namespace
>        return nil if klass.nil?
>      end
>
>      klass.eldest_ancestor_with_const(name)
>    end
>  end
> end
>
>
Something like this:

def find_const_parent(name)
  Object.constants.select do |x|
    x=eval(x)
    [Class,Module].include?(x.class) && x.const_defined?(name)
  end
end


Regards,

Park Heesob