Mongoid::Enum

Heavily inspired by DHH's ActiveRecord::Enum, this little library is just 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.

Installation

Add this to your Gemfile:

gem "mongoid-enum"

And then run bundle install.

Usage

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

Features

Field

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.

Accessors

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.

Constants

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]

Validations

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

Scopes

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

Options

Default value

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 => ""

Multiple values

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]

Validations

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], :validation => false