Methods

Instance Public methods

generate_unique_secure_token(length: MINIMUM_TOKEN_LENGTH)

📝 Source code 
# File activerecord/lib/active_record/secure_token.rb, line 43
      def generate_unique_secure_token(length: MINIMUM_TOKEN_LENGTH)
        SecureRandom.base58(length)
      end
🔎 See on GitHub

has_secure_token(attribute = :token, length: MINIMUM_TOKEN_LENGTH)

Example using has_secure_token

# Schema: User(token:string, auth_token:string)
class User < ActiveRecord::Base
  has_secure_token
  has_secure_token :auth_token, length: 36
end

user = User.new
user.save
user.token # => "pX27zsMN2ViQKta1bGfLmVJE"
user.auth_token # => "tU9bLuZseefXQ4yQxQo8wjtBvsAfPc78os6R"
user.regenerate_token # => true
user.regenerate_auth_token # => true

SecureRandom::base58 is used to generate at minimum a 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.

📝 Source code 
# File activerecord/lib/active_record/secure_token.rb, line 32
      def has_secure_token(attribute = :token, length: MINIMUM_TOKEN_LENGTH)
        if length < MINIMUM_TOKEN_LENGTH
          raise MinimumLengthError, "Token requires a minimum length of #{MINIMUM_TOKEN_LENGTH} characters."
        end

        # 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: length) }
        before_create { send("#{attribute}=", self.class.generate_unique_secure_token(length: length)) unless send("#{attribute}?") }
      end
🔎 See on GitHub