module PgSearch::Multisearchable

def self.included mod
  mod.class_eval do
    has_one :pg_search_document,
      :as => :searchable,
      :class_name => "PgSearch::Document",
      :dependent => :delete
    after_save :update_pg_search_document,
      :if => lambda { PgSearch.multisearch_enabled? }
  end
end

def update_pg_search_document
  if_conditions = Array(pg_search_multisearchable_options[:if])
  unless_conditions = Array(pg_search_multisearchable_options[:unless])
  should_have_document =
    if_conditions.all? { |condition| condition.to_proc.call(self) } &&
    unless_conditions.all? { |condition| !condition.to_proc.call(self) }
  if should_have_document
    unless pg_search_document.present?
      build_pg_search_document.searchable_type = self.class.name
    end
    pg_search_document.save
  else
    pg_search_document.destroy if pg_search_document
  end
end