Rails recently introduced
has_secure_token but it’s very primitive.
Meet the competition.
Minimum requirements are:
- Rails 4.0.0+
- Ruby 2.0.0+
Add this line to your application’s Gemfile:
And then execute:
Or install it yourself as:
$ gem install uniqueness
Adds random field support to Rails models.
To auto-generate a new random string for field
class Example < ActiveRecord::Base has_unique_field :foo end
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 (
after_initialize), default to :before_validation
:length number of characters, defaults to 32
:type type of string, can be one of:
: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
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
To regenerate a unique-random value with the same options
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.