From: Jacob Fugal <lukfugl@...>
Date: 2006-02-02T01:26:28+09:00
Subject: Re: callbacks, events, notification in general

On 2/1/06, Damphyr <damphyr@freemail.gr> wrote:
> class A
>    def set_callback notify
>      @notify=notify
>    end
>    def something
>      puts "something"
>      send(@notify) if @notify
>    end
> end
>
> def coocoo
>         puts "hey"
> end
> a=A.new
> a.something
> a.set_callback(:coocoo)
> a.something

I second Ara's mention of the Observable module. That said, I'd also
simplify this particular example using a block:

  class A
    def set_callback( &blk )
      @notify = blk
    end
    def something
      puts "something"
      @notify.call if @notify
    end
  end

  a = A.new
  a.something
  a.set_callback { puts "hey" }
  a.something

My general rule of thumb is that if something needs to be *done*, I
register a proc, but if someone needs to *know*, I register an
observer (using Observable).

Jacob Fugal