This library is a quick and simple way to generate unique, random tokens for your mongoid documents, in the cases where you can't, or don't want to use slugs, or the default MongoDB IDs.

Mongoid::Token can help turn this:

http://myawesomewebapp.com/video/4dcfbb3c6a4f1d4c4a000012/edit

Into something more like this:

http://myawesomewebapp.com/video/83xQ3r/edit

As of version 1.1.0, Mongoid::Token now supports Mongoid 3.x.

If you still require Mongoid 2.x support, please install Mongoid::Token 1.0.0.

In your gemfile, add:

gem 'mongoid_token', '~> 1.1.0'

Then update your bundle

$ bundle update

In your Mongoid documents, just add include Mongoid::Token and the token method will take care of all the setup, like so:

class Person
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Token

  field :first_name
  field :last_name

  token :length => 8
end

Obviously, this will create tokens of 8 characters long - make them as short or as long as you require.

Note: Mongoid::Token leverages Mongoid's 'safe mode' by automatically creating a unique index on your documents using the token field. In order to take advantage of this feature (and ensure that your documents always have unique tokens) remember to create your indexes.

See 'Token collision/duplicate prevention' below for more details.

The token method has a couple of key options: length, which determines the length (or maximum length, in some cases) and contains, which tells Mongoid::Token which characters to use when generating the token.

The options for contains are as follows:

• :alphanumeric - letters (upper and lowercase) and numbers
• :alpha - letters (upper and lowercase) only
• :numeric - numbers only, anything from 1 character long, up to and length
• :fixed_numeric - numbers only, but with the number of characters always the same as length

You can also rename the token field, if required, using the :field_name option:

• token :contains => :numeric, :field_name => :purchase_order_number

• token :length => 8, :contains => :alphanumeric generates something like 8Sdc98dQ
• token :length => 5, :contains => :alpha gereates something like ASlkj
• token :length => 4, :contains => :numeric could generate anything from 0 upto 9999 - but in a random order
• token :length => 4, :contains => :fixed_numeric will generate anything from 0000 to 9999 in a random order

The library also contains a finder method for looking up your documents called find_by_token, e.g:

Person.find_by_token('7dDn8q')

If you've got an app with existing data that you would like to add tokens to - all you need to do is save each of your models and they will be assigned a token, if it's missing.

Mongoid::Token leverages Mongoid's 'safe mode' by automatically creating a unique index on your documents using the token field. In order to take advantage of this feature (and ensure that your documents always have unique tokens) remember to create your indexes.

You can read more about indexes in the Mongoid docs.

Additionally, Mongoid::Token will attempt to create a token 3 times before eventually giving up and raising a Mongoid::Token::CollisionRetriesExceeded exception. To take advantage of this, one must set persist_in_safe_mode = true in your Mongoid configuration.

The number of retry attempts is adjustable in the token method using the :retry options. Set it to zero to turn off retrying.

• token :length => 6, :retry => 4 Will retry token generation 4 times before bailing out
• token :length => 3, :retry => 0 Retrying disabled

If you find a problem, please submit an issue (and a failing test, if you can). Pull requests and feature requests are always welcome and greatly appreciated.

Thanks to everyone that has contributed to this gem over the past year, in particular stephan778, eagleas and jamesotron. Many, many thanks - you guys rawk.