class Topic < ActiveRecord::Base acts_as_paranoid column: :hidden_at include ActsAsParanoidAliases include Notifiable belongs_to :community belongs_to :author, -> { with_hidden }, class_name: 'User', foreign_key: 'author_id' has_many :comments, as: :commentable validates :title, presence: true validates :description, presence: true validates :author, presence: true scope :sort_by_newest, -> { order(created_at: :desc) } scope :sort_by_oldest, -> { order(created_at: :asc) } scope :sort_by_most_commented, -> { reorder(comments_count: :desc) } end