From: Logan Capaldo <logancapaldo@...>
Date: 2006-04-27T10:37:58+09:00
Subject: Re: Extending Methods


On Apr 26, 2006, at 9:26 PM, Geoff Stanley wrote:

>
> I don't want to use inheritence and super because that would mean each
> plugin would create its own child class of the base class it wants to
> modify. This causes two problems: 1) The child classes wouldn't do
> anything; They'd have to be hooked into the main program somehow...
> troublesome and 2) The child classes wouldn't work together. If I have
> two plugins modifying the same method in the same base class, they  
> both
> need to be able to modify it, not one overruling the other.
>

Sound's like you need to make a more formal design to me then:

class Plugin
   def initialize_delta(other_self)
     # Stuff that needs to be in the initialize of the plugin
   end
end

class NormalMainClass
    def self.add_plugin(plugin)
       @plugins ||= []
       @plugins << plugin
    end
    def self.plugins
       @plugins ||= []
    end

    def initialize
        # generic initialization here
        self.class.plugins.each do |plugin|
           instance_eval(&plugin.method(:initialize_delta))
        end
    end
end

# main part of program

# load plugins from files

NormalMainClass.add_plugin(Plugin)

obj = NormalMainClass.new

Of course the way of outlined this may not be appropriate for what  
you want to do, but it should give you some ideas. Just because ruby  
_can_ do a lot of stuff auto-magically doesn't mean you have to, when  
it's not specific enough for you. (Note also this code is totally  
untested, I may have message something up).