From: Dan Doel <djd15@...>
Date: 2003-08-26T04:25:06+09:00
Subject: Re: Aspect oriented Everything?

Martin DeMello wrote:

>No, because mixins don't let you wrap methods. You can use mixins if
>you've designed your code from the start to use mixins that way, but you
>can't add them to abn existing codebase (whereas, from what I gather,
>you can with aspects).
>

Actually:

class Foo
    def bar(a)
        @a = a
    end
end

module Aspect
    def Aspect.append_features(c)
        c.class_eval do
            alias_method :oldbar, :bar

            def bar(a)
                puts a
                oldbar a
            end
        end
       
        super
    end
end

class Foo
    include Aspect
end

Foo.new.bar 55

- Dan

P.S.: I tried doing this by putting the new "def bar(a) ..." stuff in 
the instance methods of the Aspect module,
but it doesn't seem to add them.  I'm calling super in append_features, 
and I tried doing "super c", but that
didn't work either. What am I doing wrong?