Tokenable concern for Rails models

tokenable.rb

# app/models/concerns/tokenable.rb

module Tokenable
  extend ActiveSupport::Concern

  included do
    before_create :generate_token
  end

  protected

  def generate_token
    max_attempts = 0
    self.token = loop do
      random_token = SecureRandom.urlsafe_base64(nil, false)
      break random_token unless self.class.exists?(token: random_token)
      attempts = attempts + 1
      raise "Max attempts to generate token reached" if attempts > max_attempts
    end
  end
end