class Grade < ApplicationRecord belongs_to :user has_many :tidings, :as => :container, :dependent => :destroy after_create :send_tiding def send_tiding self.tidings << Tiding.new(:user_id => self.user_id, :trigger_user_id => 0, :parent_container_id => self.container_id, :parent_container_type => self.container_type, :viewed => 0, :tiding_type => "System") end end