From: ara.t.howard@...
Date: 2006-02-24T01:13:29+09:00
Subject: Re: Converting a string to a class

On Fri, 24 Feb 2006, James Edward Gray II wrote:

> On Feb 23, 2006, at 9:07 AM, Anthony DeRobertis wrote:
>
>> Gregory Brown wrote:
>> 
>>> On 2/22/06, Anthony DeRobertis <aderobertis@metrics.net> wrote:
>>>> Take the following snippet:
>>> 
>>> why do string conversion?
>>> 
>>> You can pass constants around in ruby just fine.
>> 
>> I'm scanning a directory for plugins and loading them. When I load a
>> file called, for example, some_plugin.rb, I assume it creates a class
>> Whatever::Plugins::SomePlugin, which I naturally only have as a
>> string...
>
> You can do this without using the name assumptions in Ruby, if you give them 
> a class to inherit from.  Classes get notified when they are subclassed:
>
>>> class Plugin
>>>   def self.inherited( plugin_class )
>>>     (@@plugins ||= Array.new) << plugin_class
>>>   end
>>>   def self.loaded
>>>     @@plugins || Array.new
>>>   end
>>> end
> => nil
>>> class FirstPlugin < Plugin; end
> => nil
>>> class SecondPlugin < Plugin; end
> => nil
>>> Plugin.loaded
> => [FirstPlugin, SecondPlugin]
>
> Hope that gives you some fresh ideas.

i've abstracted this pattern as the 'dynaload' library here

   http://rubyforge.org/frs/?group_id=1024&release_id=3786

regards.

-a

-- 
judge your success by what you had to give up in order to get it.
- h.h. the 14th dali lama