module ActiveRecord::SecureToken::ClassMethods

Public Instance Methods

generate_unique_secure_token(length, prefix) click to toggle source
# File lib/super_token.rb, line 36
def generate_unique_secure_token(length, prefix)
  token_length = length - prefix.length
  prefix + SecureRandom.base58(token_length)
end
has_secure_token(attribute = :token, length: 24, prefix: '') click to toggle source

Example using has_secure_token

# Schema: User(token:string, auth_token:string, api_key:string)
class User < ActiveRecord::Base
  has_secure_token
  has_secure_token :auth_token, prefix: 'ut_'
  has_secure_token :api_key,    prefix: 'ak_', length: 42
end

user = User.new
user.save
user.token # => "pX27zsMN2ViQKta1bGfLmVJE"
user.auth_token # => "77TMHrHJFvFDwodq8w7Ev2m7"
user.api_key # => "ak_1wkenr7vcAb9tH1jyQzvBdxBg8jC2bSv8ySM335"
user.regenerate_token # => true
user.regenerate_auth_token # => true

SecureRandom::base58 is used to generate the 24-character unique token, so collisions are highly unlikely.

Note that it's still possible to generate a race condition in the database in the same way that validates_uniqueness_of can. You're encouraged to add a unique index in the database to deal with this even more unlikely scenario.

# File lib/super_token.rb, line 29
def has_secure_token(attribute = :token, length: 24, prefix: '')
  # Load securerandom only when has_secure_token is used.
  require 'active_support/core_ext/securerandom'
  define_method("regenerate_#{attribute}") { update! attribute => self.class.generate_unique_secure_token(length, prefix) }
  before_create { self.send("#{attribute}=", self.class.generate_unique_secure_token(length, prefix)) unless self.send("#{attribute}?")}
end