RandomizedField

RandomizedField is a simple module for ActiveRecord that populates a field with a unique, randomly-generated string. This is useful for generating one-off tokens or creating a non-incrementing unique ID.

Oftentimes we want a randomized unique ID so that we don't reveal information about how large our database is or to create an unguessable (and perhaps temporary) token for things like password resets, etc.

You might use RandomizedField to generate:

• Order numbers, return authorization numbers, etc. for an e-commerce system
• Unique referral IDs or invitation tokens for each user of your site
• Tokens for password reset emails
• Temporary tokens embedded in an email that automatically log users in

1. Add the randomized_field gem to your application's Gemfile:

   gem 'randomized_field'

2. Run bundle to install the gem

   $ bundle

   Or install it directly with the gem command:

   $ gem install randomized_field

3. Include RandomizedField in the models you care about (or in a shared base class like ApplicationRecord if you want it available to every model):

   class Article < ApplicationRecord
     include RandomizedField
   
     randomized_field :slug, length: 10
   end

Note: RandomizedField won't do anything unless you also call randomized_field with the name of the field you want to populate.

Including RandomizedField in a model will define a class-level randomized_field method. The only required argument is the name of the field to populate, but there are a few optional arguments. You can supply one or more of them.

class Article < ApplicationRecord
  # Control the length of the generated string.
  # Default is 8.
  randomized_field :slug, length: 10
end

class Article < ApplicationRecord
  # Control the characters used to generate the string.
  # Default is ('0'..'9') + ('a'..'z').
  randomized_field :slug, valid_characters: %w[a b c]
end

class Article < ApplicationRecord
  # Pass in a block that is passed the randomly generated string, but is called
  # before setting the vaue. This allows you to transform the value, e.g.,
  # adding a prefix, suffix, etc.
  # Default is a no-op (don't transform the value)
  randomized_field :slug do |slug_value|
    "prefix_" + slug_value + "_suffix
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. 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.

Bug reports and pull requests are welcome on GitHub at https://github.com/jfarmer/randomized_field.

The gem is available as open source under the terms of the MIT License. See the LICENSE.txt file.