From: Joel VanderWerf <vjoel@...>
Date: 2007-12-17T10:56:20+09:00
Subject: Re: text file to code?

Pavel Pvl wrote:
> earlier i asked if its possible to load a string as code. but now, lets
> say i have a config file. a text file with ruby code in it. how can i
> load that into my ruby code? but for that matter, everytime it does load
> it, can it read as a new object? like lets say the config file consists
> of "plugins" and i add one, can ruby pick it up while the app is
> running?

You can do that by wrapping the loaded code in a module, and then using 
that module to access any constants or functions defined in the code. 
Here's how I do that:

http://redshift.sourceforge.net/script/

An adaptation of this is in the facets gem, IIRC. The basic idea is 
simple (suggested by Nobu Nokada):

   def load_in_module(file)
     module_eval(IO.read(file), File.expand_path(file))
   end

This returns a module that you can use to get at stuff in the file:

   m = load_in_module(file)
   m::SomeClass
   m.some_method

The code above assumes that the file has these definitions:

   class SomeClass;...end
   def self.some_method;...end

An alternative:

http://codeforpeople.com/lib/ruby/dynaload/

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407