Internal plugin architecture, where to start from

Hello folks.
I am refactoring a simple CMS, and looking to implement a simple
internal plugin architecture.
I have a MenuItem class. By default, menu items can be, say, ‘article’
or ‘sitemap’, or ‘newsroll’. I want to implement a hook to which my
modules can plug, so I will be able to add other tipologies (like
“catalog”, “gallery” or whatever) through modules, which are aptly
structured plugins.
Presently, I have something like this:

class MenuItem < ActiveRecord::Base belongs_to :article @tipologies = @tipologies.push("article","sitemap") def self.tipologies return @tipologies end def self.addTipology(item) @tipologies.push(item) end end
I have been able to add an item to @typologies through a plugin, with
this init.rb

ActionController::Base.send :include,  Tipeadder

And this is the main plugin code (obviously I am just sketching here):

# Tipeadder.rb module Tipeadder MenuItem.addTipology("cane") MenuItem.addTipology("gatto") end

Yet the type is added only when the app is first loaded, then it gets
I am a also bit lost here. I have been using plugin architectures for
ages in Wordpress development, but never implemented one, so i am not
sure I am going the right way.
Have you go some general advice on the procedure I should follow? Which
is the best and most ruby-like way to do this?