From: Pit Capitain <pit@...>
Date: 2002-08-04T23:34:41+09:00
Subject: Re: Detecting when an instance variable is created/set

On 4 Aug 2002, at 22:42, Harry Ohlsen wrote:

> To give you a feel for what I want to do ...
> 
> In the constructor of, say, Album, I'd like something like this,
> without forcing the user to write the "Wrapper.new()"
> 
>    class Album
>       def initialize(title, songs)
>          @title    = Wrapper.new(title)
>          @songs = songs.map { |s| Wrapper.new(s) }
>       end
>    end
> 
> Ie, what I want the user to be able to write is
> 
>    class Album
>       def initialize(title, songs)
>          @title    = title
>          @songs = songs
>       end
>    end
> 
> Now, if I could catch the "@x = ..." lines I could automate this.
> 
> Actually, in my real system, I would only modify what gets stored in
> @songs, not what gets stored in @title, but I have a way to determine
> whether I need to make the conversion.
> 

Hi Harry,

if you cange the initialize method to

  def initialize(title, songs)
    self.title = title
    self.songs = songs
  end

the accessor methods are called.

Regards,
Pit