Re: [Rubycocoa-talk] adding to attr_accessor.

[Tom C. <ta...@ca...>]

Hello Dave

On 15 Jul 2005, at 04:25, Dave Howell wrote:
> Well, yes, but that was my point. I hadn't the faintest how to do  
> that. I find symbols still quite mysterious.

I find it easiest to think of symbols as strings that never change.   
You can often use a string in place of a symbol (attr_accessor  
"title" works the same as attr_accessor :title) but symbols are one  
character less, and send a signal to anyone reading your code that  
the string is for internal use only (ie it won't be shown on the  
screen to the user).

> Looking at your example, I see I'm going to have to go read up  
> on .class_eval, define_method, and instance_variable, all of which  
> I didn't even know I was looking for. :) But that sure looks like  
> exactly what I wanted to know. Thanks!

You may also want to look at the Observer class that is built into  
ruby http://www.ruby-doc.org/stdlib/libdoc/observer/rdoc/index.html  
which reduces the code you need to type a bit.

Tom