From: Kevin Mahler <kevin.mahler@...>
Date: 2011-04-15T10:07:16+09:00
Subject: Re: What do you do when you need to attach data to an object instance?

Aaron D. Gifford wrote in post #992887:
>  def extend_accessor(obj, name)
>    mod = Module.new
>    mod.send(:public).send(:attr_accessor, name.to_sym)
>    obj.extend(mod)
>    obj
>  end

Or more compactly,

  def extend_accessor(obj, name)
    obj.extend Module.new { attr_accessor name }
    obj
  end

But that's an odd maneuver anyway. My original example extended an
object with a specified, named mixin. For ad hoc methods the singleton
class is more natural.

  def extend_accessor(obj, name)
    obj.singleton_class.module_eval { attr_accessor name }
    obj
  end

You probably found a bug with attr_accessor; it should produce public
methods in any context, I think. Nobody has encountered the bug
because Module.new { } and module_eval { } are commonly used to do
those things, and those behave correctly.

-- 
Posted via http://www.ruby-forum.com/.