From: Eric Hodel <drbrain@...7.net>
Date: 2006-12-11T10:24:14+09:00
Subject: Re: Question on IO objects, initialize, and yaml

On Dec 10, 2006, at 12:19 , Mark Noworolski wrote:

> Say I have a class with pseudo code as follows:
> class Test
> def initialize
>  @a=1
>  @b=File.open("file+Time.now or similar")
> end
> end
>
> Now, imagine that I use this class for a while and then I want to  
> dump it to
> a YAML file.
>
> When I restart my code, I want it to read in stuff from the YAML  
> file (if it
> exists) and use that as a starting point to work from (basically, I am
> saving state in the yaml file). You'll note that I cannot just do  
> this as
> is, because reading in from YAML does not initialize the class, so  
> @b would
> not be initialized correctly on restart.

Ruby and YAML provide hooks to cause things to happen when you load  
from Marshal or YAML.  I think #initialize_copy gets called for  
Marshal, I don't know the YAML ones, but  they should be easy to find.

> I'd like to just initialize the thing, then read in the YAML file to
> overwrite the state with the saved values. Is there some extremely  
> obvious
> ruby way to do this or something equivalent?

Don't do this, use the built-in hooks, that's what they're for.

-- 
Eric Hodel - drbrain@segment7.net - http://blog.segment7.net

I LIT YOUR GEM ON FIRE!