acts_as_sane_nested_attributes.rb

module Sanity
  module ActsAsSaneNestedAttributes
    def self.included(base)
      base.extend(ClassMethods)
    end

    module ClassMethods
      def acts_as_sane_nested_attributes(options = [])
        puts 'Setting up child callbacks'
        ActiveRecord::Callbacks::CALLBACKS.each do |callback|
          options.to_a.each do |child|
            puts "Checking if #{child} supports #{callback}"
            if child.to_s.classify.constantize.send(callback.to_sym).any?
              puts "Setting #{callback} for #{child}"
              self.send(callback.to_sym, "#{child.to_s.pluralize}.each{|c| c.run_callbacks(#{callback.to_sym})}")
            end
          end
        end
      end
    end
  end
end

ActiveRecord::Base.send :include, Sanity::ActsAsSaneNestedAttributes