From: Robert Dober <robert.dober@...>
Date: 2007-05-07T00:25:15+09:00
Subject: Re: how to define a method template

On 5/6/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> On 06.05.2007 13:14, Robert Dober wrote:
> > On 5/6/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> >> On 06.05.2007 10:36, Nanyang Zhan wrote:
> >> > Forgive me for the nonstandard words. I will describe my problem in
> >> > details:
> >> > I am doing a rails app, and met a ruby problem.
> >> > Inside a model class, I will need to write these codes for "apple"
> >> > def apple_attr
> >> >  apples.collect {|o| o.name}.join(" ")
> >> > end
> >> >
> >> > def apple_attr=(str)
> >> >  @apple = str
> >> > end
> >> >
> >> > def save_apple
> >> >  #lots of codes
> >> > end
> >> >
> >> > then banana, cat, dog.. each will have a copy of above codes. They are
> >> > the same, except replacing the word "apple" with "banana", "cat",
> >> > "dog"....
> >> >
> >> > I know there is a way to put these code in to a module, then mixin the
> >> > module with current class, after that, you just need to call a method
> >> > (like setup_methods(:apple); setup_methods(:dog)...), instead of typing
> >> > the repeated code.
> >> >
> >> > Would any one tell me how to do it?
> >>
> >> Why not create all the methods on the fly?  Like
> >>
> >> class Foo
> >>    def setup_methods(sym)
> >>      cl = class <<self;self;end
> >>      cl.class_eval do
> >>        attr_accessor sym
> >>      end
> >>      cl.class_eval "def #{sym}_save() puts 'saving #{sym}' end"
> >>    end
> >> end
> > Robert I have understood the setup a little bit differently, was it
> > not on the class base that OP wanted his methods?
>
> Maybe.  His statement seems to be a bit contradictory.  First he talks
> about all these methods being there.  Then he mentions some method
> setup_methods which I believe is to create those methods.  But you're
> right, could also be a class method (like attr_accessor).  OP, what do
> you want - Robert's solution or Robert's solution? :-)
Difficult decision LOL
>
> Kind regards
>
>         robert
>
>


-- 
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw