class Comment < ActiveRecord::Base

  belongs_to :post, inverse_of: :comments

  after_save :update_post_updated_at, source: :post
  before_create :set_post_title
  before_save :update_post_title, source: :post
  after_destroy source: :post do |comment, post|
    comment.update_attributes!(orphan_from_id: post.id)
  end

  private

  def set_post_title
    self.post_title = post.title
  end

  def update_post_title(post)
    update_attributes!(post_title: post.title) if post.title_changed?
  end

  def update_post_updated_at
    update_attributes!(post_updated_at: post.updated_at)
  end

end