From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-08-20T16:26:31+09:00
Subject: Re: some method help ... not really sure about proper title

On Tue, Aug 19, 2008 at 10:23 PM, Lex Williams <etaern@yahoo.com> wrote:
> Hi guys!
>
> I'm kinda new to ruby , and was wondering about the following stuff ,
> assume the following code :
>
> Shoes.app {
>  button("Press Me") { alert("You pressed me") }
> }
>
> how could I write code like that , so that when I call a method like
> button , I don't have to put an object or a class name in front of it .
>
> To give another example , let's assume the following code :
>
> class Whatever
>   attr_accessor :value
>
>   def initialize
>      yield self
>   end
>
>   def some_method
>      puts "some method"
>   end
>
> end
>
> I would like to do the following ( if it's possible ) :
>
> w = Whatever.new do |whatever|
>        some_method
>        value = 20
> end
>
> puts w.value # this should output 20
>
> Is this possible , without adding those methods to Object ?

Hi, if you use the following you can call certain methods like you want.

 class Whatever
   attr_accessor :value

   def initialize &blk
      instance_eval &blk
   end

   def some_method
      puts "some method"
   end
 end

This will allow to do:

w = Whatever.new {some_method}

The only exception are the xxx= methods. This won't work:

w = Whatever.new {value = 20}

The reason is that value= methods have to be called as self.value=20
within the class, because it's
the only way for the interpreter to understand that you want a method
call and not a local variable to the
function. You could do:

w = Whatever.new {self.value = 20}

That works.

Hope this gives you some other ideas...

Jesus.