ActiveRecord (rails) token authenticable module

token_authenticable.rb

module TokenAuthenticatable
  extend ActiveSupport::Concern

  module ClassMethods
    def find_by_authentication_token(authentication_token = nil)
      if authentication_token
        where(authentication_token: authentication_token).first
      end
    end
  end

  def ensure_authentication_token
    if authentication_token.blank?
      reset_authentication_token!
    end
  end

  def reset_authentication_token!
    self.authentication_token = generate_authentication_token
    authentication_token_updated
  end

  def clear_authentication_token!
    self.authentication_token = nil
    authentication_token_updated
  end

  private

  def authentication_token_updated
    self.authentication_token_generated_at = DateTime.now
    update_record_without_timestamping
  end

  def generate_authentication_token
    loop do
      token = SecureRandom.urlsafe_base64(16)
      break token unless User.exists?(authentication_token: token)
    end
  end

  # update without recording new timesamps

  def update_record_without_timestamping
    class << self
      def record_timestamps; false; end
    end

    save!

    class << self
      remove_method :record_timestamps
    end
  end
end