From: Robert Klemme <bob.news@...>
Date: 2004-07-02T17:22:48+09:00
Subject: Re: mixin question


"Ara.T.Howard" <Ara.T.Howard@noaa.gov> schrieb im Newsbeitrag
news:Pine.LNX.4.60.0407011009461.25990@harp.ngdc.noaa.gov...
>
>
> i have this
>
>    jib:~ > cat a.rb
>    module M
>      def bar
>        @bar = 42
>        super
>      end
>    end
>    class Foo
>      attr :bar
>      def initialize
>        @bar = 'bar'
>      end
>    end
>
>    foo = Foo.new
>    p foo.bar
>
>    class Foo
>      include M  # of course this acts as super - it does not override
>    end
>
>    p foo.bar
>
>
>    jib:~ > ruby a.rb
>    "bar"
>    "bar"
>
> and i want it to print "bar", "42".  i'm looking for a way to overide
all of a
> classes methods via a module (or some other trick) without needing to
extend
> individual objects and without simply opening up the class and
redefining
> everything.  in otherwords a simple way to override a bunch of bundled
methods
> at once.  it seems like this must be possible but my brain isn't firing
on all
> fours today...

Does this help?

module M
  def self.included(cl)
    cl.instance_eval do
      instance_methods.each do |meth|
        define_method(meth) do |*args|
          p args
        end
      end
    end
  end

  def bar
    @bar = 42
    super
  end
end

class Foo
  attr :bar
  def initialize
    @bar = 'bar'
  end
end

foo = Foo.new
p foo.bar

class Foo
  include M  # of course this acts as super - it does not override
end

p foo.bar


Of course the method definition has to be made a bit smarter.

Regards

    robert