From: sera@... (Francis Hwang)
Date: 2004-06-05T04:08:40+09:00
Subject: Re: Can an inner class get its container at runtime?

Works like a charm, thanks! Ah, Ruby reflection.

Francis

Mark Hubbart <discord@mac.com> wrote in message news:<09241422-B0F3-11D8-8419-000502FDD5CC@mac.com>...
> On May 28, 2004, at 1:33 PM, Francis Hwang wrote:
> 
> > Is there a way for an inner class to find out what class owns it? The
> > code I'd like to use looks like:
> >
> > class AbstractInnerClass
> >   def do_something
> >     # here's where I need to find the owner of the concrete child
> >   end
> > end
> >
> > class OuterClass
> >   class ConcreteInnerClass < AbstractInnerClass
> >   end
> > end
> >
> > I'd love to be able to call ConcreteInnerClass#do_something and know
> > that it can find OuterClass. Is there a way for me to do this?
> 
> Maybe like this?
> 
>    class AIC
>      def my_container_class
>        Object.const_get self.class.to_s.split(/::/)[0...-1].join("::")
>      end
>    end
>      ==>nil
>    class Out
>      class In < AIC
>      end
>    end
>      ==>nil
>    Out::In.new.my_container_class
>      ==>Out
> 
> This will give an error if there is no outer class, but you should be 
> able to wrap the core code line in a begin...rescue block and/or check 
> the string to ensure non-emptyness before calling Object.const_get with 
> it.
> 
> HTH,
> Mark