From: Dave Burt <dave@...>
Date: 2005-08-13T11:11:12+09:00
Subject: Re: eval, attr_* like methods

Patrick Gundlach asked:
> ... since this
> lookup_meth is defined in Ojbect, it might get overridden by another
> method definition of the same name, right? Is it possible to move this
> definition somewhere 'closer' to my classes?

You can define your lookup_meth in the target class directly:
  class Test
    def self.lookup_meth(*args)
      #...
    end
    lookup_meth :test1, :test2
  end

Or you can define it in a module, and extend the classes you want to use it 
in:
  module LookupMeth
    def lookup_meth(*args)
      #... (no changes required here)
    end
  end
  class Test
    extend LookupMeth
    lookup_meth :test1, :test2
  end

> And number two: I have
> one variable that I need to check. Example:
>
>  def self.lookup_meth(*args)
>    args.each do | name |
>      eval %(
>      def #{name}
>        if @othervar    #  <-----------
>          puts "hello"
>        end
> @#{name} ||= '24'
>      end
>
> Any way to avoid a warning about 'instance variable @othervar not
> initialized'?

You can initialize the variable the line before:
  @othervar ||= nil
Or you can change your if condition:
  if defined?(@otherbar) && @othervar

Cheers,
Dave