From: Thiago Arrais <thiago.arrais@...>
Date: 2006-04-02T02:03:51+09:00
Subject: Dynamic code generation

I have been trying to do some simple dynamic code generation in Ruby.
What I am specifically trying is to redefine a class level method on
the subclasses. I know I may achieve that by using a simple def, but I
would like come up with a simpler syntax, something like this:

----
class Parent
    def self.redefinable_method
        return "This is the default string returned when the method
isn't redefined"
    end

    def redefinable_method
        return self.class.redefinable_method
    end
end

class FirstChild < Parent
    redefine "This is the custom string for the FirstChild class"
end

class SecondChild < Parent; end

fst = FirstChild.new
fst.redefinable_method => "This is the custom string for the FirstChild class"

snd = SecondChild.new
snd.redefinable_method => "This is the default string returned when
the method isn't redefined"
----

In this example you can see two points: (a) I am a total newbie, (b)
the method 'redefine' should be defined on the parent class, but I
don't have a clue on how it should be written. I have taken a look at
ActiveRecord's associations, but it seems like overkill to use the
exact same approach.

Two questions:

Is it possible to do that?
Can the client code (child classes) be made any simpler/shorter?

Cheers,

Thiago Arrais