class Bulb < ActiveRecord::Base default_scope { where(name: "defaulty") } belongs_to :car, touch: true scope :awesome, -> { where(frickinawesome: true) } attr_reader :scope_after_initialize, :attributes_after_initialize after_initialize :record_scope_after_initialize def record_scope_after_initialize @scope_after_initialize = self.class.all end after_initialize :record_attributes_after_initialize def record_attributes_after_initialize @attributes_after_initialize = attributes.dup end def color=(color) self[:color] = color.upcase + "!" end def self.new(attributes = {}, &block) bulb_type = (attributes || {}).delete(:bulb_type) if bulb_type.present? bulb_class = "#{bulb_type.to_s.camelize}Bulb".constantize bulb_class.new(attributes, &block) else super end end end class CustomBulb < Bulb after_initialize :set_awesomeness def set_awesomeness self.frickinawesome = true if name == "Dude" end end class FunkyBulb < Bulb before_destroy do raise "before_destroy was called" end end class FailedBulb < Bulb before_destroy do throw(:abort) end end class TrickyBulb < Bulb after_create do |record| record.car.bulbs.to_a end end