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Rails recently introduced has_secure_token but it's very primitive. Meet the competition.

Code Documentation


Minimum requirements are:

  1. Rails 4.0.0+
  2. Ruby 2.0.0+


Add this line to your application's Gemfile:

gem 'uniqueness'

And then execute:

$ bundle

Or install it yourself as:

$ gem install uniqueness


Adds random field support to Rails models.

To auto-generate a new random string for field foo:

class Example < ActiveRecord::Base
  has_unique_field :foo

You can customize the generated string by passing an options hash. The following keys are supported:

:trigger_on when to be generated, can be one of ActiveRecord callbacks (before_validation, before_create, before_save, after_initialize), default to :before_validation

:length number of characters, defaults to 32

:type type of string, can be one of: :human, :auto, defaults to :auto

Human type generates strings easier to read by excluding ambiguous characters like 1, 5, 8, B, o, O, I, l, s, u.

:blacklist characters to exclude when generating the random string, defaults to []

:scope scopes, defines the ActiveRecord scope applied before calculating the position field value. Defaults to []

To generate a unique-random on the fly Uniqueness.generate that will produce a random field for you.

You can also pass some options Uniqueness.generate(type: :human).

To regenerate a unique-random value with the same options example.regenerate_foo.


After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.


Please see CONTRIBUTING.md for details.



Project is sponsored by Eventtus.