Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!news.dougwise.org!nntpfeed.proxad.net!proxad.net!feeder1-2.proxad.net!usenet-fr.net!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!talisker.lacave.net!lacave.net!not-for-mail
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
Organization: Service de news de lacave.net
Lines: 32
Message-ID: <ebf5e68c050f1d14ab1e4188d6d392c2@ruby-forum.com>
References: <BANLkTinVjc-Lv4LYB6ODXCRDnrDOQj+2uA@mail.gmail.com> <6fce5b6386258c51794d0b55b63e1ed6@ruby-forum.com> <BANLkTi=ih21apYDBBBgDpVkfJcRXR6CmJg@mail.gmail.com> <BANLkTinGsu4_yM51dETQBgrN4c4enz1FaA@mail.gmail.com>
NNTP-Posting-Host: bristol.highgroove.com
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
X-Trace: talisker.lacave.net 1302830333 19300 65.111.164.187 (15 Apr 2011 01:18:53 GMT)
X-Complaints-To: abuse@lacave.net
NNTP-Posting-Date: Fri, 15 Apr 2011 01:18:53 +0000 (UTC)
In-Reply-To: <BANLkTinGsu4_yM51dETQBgrN4c4enz1FaA@mail.gmail.com>
X-Received-From: This message has been automatically forwarded from the ruby-talk mailing list by a gateway at comp.lang.ruby. If it is SPAM, it did not originate at comp.lang.ruby. Please report the original sender, and not us. Thanks! For more details about this gateway, please visit: http://blog.grayproductions.net/categories/the_gateway
X-Mail-Count: 381596
X-Ml-Name: ruby-talk
X-Rubymirror: Yes
X-Ruby-Talk: <ebf5e68c050f1d14ab1e4188d6d392c2@ruby-forum.com>
Xref: x330-a1.tempe.blueboxinc.net comp.lang.ruby:2906

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/.