class Impression < ActiveRecord::Base belongs_to :impressionable, :polymorphic=>true after_save :update_impressions_counter_cache private def update_impressions_counter_cache impressionable_class = self.impressionable_type.constantize if impressionable_class.counter_cache_options resouce = impressionable_class.find(self.impressionable_id) resouce.try(:update_counter_cache) end end end