Heavily inspired by DHH's ActiveRecord::Enum, this little library is there to help you cut down the cruft in your models and make the world a happier place at the same time.

A single line will get you fields, accessors, validations and scopes, and a few other bits-and-bobs.

Add this to your Gemfile:

gem "mongoid-enum"

And then run bundle install.

class Payment
  include Mongoid::Document
  include Mongoid::Enum

  enum :status, [:pending, :approved, :declined]
end

Aaaaaaand then you get things like:

payment = Payment.create

payment.status
# => :pending

payment.approved!
# => :approved

payment.pending?
# => :false

Payment.approved
# => Mongoid::Criteria for payments with status == :approved

Your enum value is stored as either a Symbol, or an Array (when storing multiple values). The actual field name has a leading underscore (e.g.: _status), but is also aliased with its actual name for you convenience.

Your enums will get getters-and-setters with the same name. So using the Payment example above:

payment.status = :declined
payment.status
# => :declined

And you also get bang(!) and query(?) methods for each of the values in your enum (see this example.

For each enum, you'll also get a constant named after it. This is to help you elsewhere in your app, should you need to display, or leverage the list of values. Using the above example:

Payment::STATUS
# => [:pending, :approved, :declined]

Enum values are automatically validated against the list. You can disable this behaviour (see below).

A scope added for each of your enum's values. Using the example above, you'd automatically get:

Payment.pending # => Mongoid::Criteria
Payment.approved # => Mongoid::Criteria
Payment.declined # => Mongoid::Criteria

If not specified, the default will be the first in your list of values (:pending in the example above). You can override this with the :default option:

enum :roles, [:manager, :administrator], :default => ""

Sometimes you'll need to store multiple values from your list, this couldn't be easier:

enum :roles, [:basic, :manager, :administrator], :multiple => true

# ...

user = User.create
user.roles << :basic
user.roles << :manager
user.save!

user.manager? # => true
user.administrator? # => false
user.roles # => [:basic, :manager]

Since the underlying datatype for storing values is an array, if you need to specify default(s), ensure you use an array:

enum :roles, [:noob, :author, :editor], :multiple => true, :default => [:author, :editor] # two defaults
enum :roles, [:noob, :author, :editor], :multiple => true, :default => [] # no default

Validations are baked in by default, and ensure that the value(s) set in your field are always from your list of options. If you need more complex validations, or you just want to throw caution to the wind, you can turn them off:

enum :status, [:up, :down], :validate => false

If you have any problems, or you have a suggestion, please submit an issue (and a failing test, if you can). Pull requests and feature requests are alwasy welcome and greatly appreciated.