gistfile1.txt

module OrderedSelect
  extend ActiveSupport::Concern

  included do
    def self.ordered_list(ids)
      ids_list = ids.to_s.split(',').select(&:present?)
      self.where(id: ids_list).order(ids_list.reverse.map { |id| "#{self.table_name}.id = #{id}" }.join(", "))
    end

    def self.unordered_list(ids)
      ids_list = ids.to_s.split(',').select(&:present?)
      self.where(id: ids_list)
    end
  end
end