class NewsPost < ApplicationRecord belongs_to :user validates :user_id, presence: true belongs_to :news_feed, polymorphic: true validates :news_feed_id, presence: true validates :name, presence: true, length: { maximum: 255 } validate :user_permission default_scope { order(created_at: :desc) } private def user_permission unless self.news_feed.can_post_news?(self.user) errors.add(:user, "does not have permission to post in this feed") end end end