Re: What do you do when you need to attach data to an object instance?

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From	Kevin Mahler <kevin.mahler@yahoo.com>
Newsgroups	comp.lang.ruby
Subject	Re: What do you do when you need to attach data to an object instance?
Date	Thu, 14 Apr 2011 20:07:16 -0500
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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/.

Thread

What do you do when you need to attach data to an object instance? "Aaron D. Gifford" <astounding@gmail.com> - 2011-04-14 14:47 -0500
  Re: What do you do when you need to attach data to an object instance? Kevin Mahler <kevin.mahler@yahoo.com> - 2011-04-14 16:11 -0500
    Re: What do you do when you need to attach data to an object instance? "Aaron D. Gifford" <astounding@gmail.com> - 2011-04-14 17:33 -0500
      Re: What do you do when you need to attach data to an object instance? "Aaron D. Gifford" <astounding@gmail.com> - 2011-04-14 18:45 -0500
        Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-14 19:50 -0500
        Re: What do you do when you need to attach data to an object instance? Kevin Mahler <kevin.mahler@yahoo.com> - 2011-04-14 20:07 -0500
          Re: What do you do when you need to attach data to an object instance? "Aaron D. Gifford" <astounding@gmail.com> - 2011-04-15 01:35 -0500
            Re: What do you do when you need to attach data to an object instance? Robert Klemme <shortcutter@googlemail.com> - 2011-04-15 03:46 -0500
              Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-15 13:40 -0500
                Re: What do you do when you need to attach data to an object   instance? Robert Klemme <shortcutter@googlemail.com> - 2011-04-15 21:00 +0200
          Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-15 18:10 -0500
            Re: What do you do when you need to attach data to an object instance? Kevin Mahler <kevin.mahler@yahoo.com> - 2011-04-16 10:32 -0500
              Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-16 12:14 -0500
                Re: What do you do when you need to attach data to an object instance? Kevin Mahler <kevin.mahler@yahoo.com> - 2011-04-16 12:53 -0500
                Re: What do you do when you need to attach data to an object instance? Adam Prescott <adam@aprescott.com> - 2011-04-18 07:10 -0500
  Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-14 18:15 -0500
  Re: What do you do when you need to attach data to an object instance? 7stud -- <bbxx789_05ss@yahoo.com> - 2011-04-14 19:01 -0500

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