From: "Iñaki Baz Castillo" <ibc@...>
Date: 2008-06-27T23:49:48+09:00
Subject: Re: Is it ellegant to use a global variable to store a Logger object?

El Viernes, 27 de Junio de 2008, Shot (Piotr Szotkowski) escribió:
> Iñaki Baz Castillo:
> > El Jueves, 26 de Junio de 2008, Shot (Piotr Szotkowski) escribió:
> >> module MyProgram
> >>   class Logger
> >>   class << self
> >>     def debug …
> >>       …
> >>     end
> >>   end
> >>   end
> >> end
> >
> > Ok, this seems really ellegant and I've tested that I can call
> > "Logger.debug..." in any submodule/subclass into the program :)
> >
> :)
> :
> > Just a question: Logger must use an instance of a class (real
> > class Logger), so to store it I think the best option is using
> > a @@class_variable into Logger module
>
> No – by using class << self, you’re operating on the Logger object
> (an instance of the class Class), and you can access its *instance*
> variables. 

Thanks, in fact I didn't understand the meaning of "class << self" until now.


> That’s the other elegant part about this solution – you can 
> use anything you’re used to, including, for example, attr_accessors.
>
> I use this approach like in the below code; I can use stuff like
>
> $stderr.puts 'some debug line' if Config.debug
>
> 1.upto Config.max_pins do |pin|
>   …
> end
>
> or decide whether to use Enumerable#map or the forkoff
> gem based on whether Config.processes is one or more. :)

This seems really cool. I'll try to use it.

Thanks a lot.


-- 
Iñaki Baz Castillo