How to organize modules.

Hi! I have rails application. Now I want add there some modules. I try to do it using plugins and have a problem. Maybe I doing something wrong.

I build module as a class. Each module has own class definition with necessary functionality. Now I want to access them (get list of modules for example). How should I access them?

I tried to declare a registry class in /lib and build a list of modules them (list is filled in init.rb of each module). Then I create a page where list of modules would be shown.

And now I have a problem. In first access page displays everything ok. But next access displays an empty page!

My "module registry" looks like

private_class_method :new

  def self.instance     @mod = new unless @mod     @mod   end

  def register_module (mod)     @modules = if !@modules     @modules << mod   end

  def modules     @modules = if !@modules     @modules   end

What am I doing wrong? Do you have links to articles about organization architecture like this?