ActsAsEnum

This acts_as extension for ActiveRecord 3.0 provides the capabilities for mapping a column to symbols, while adding useful scopes as well as translations.

Column may be an integer or a string. It may be something else, but it's untested.

Example

create_table :users do |t|
  t.column :sex, :integer
end

class User < ActiveRecord::Base
  acts_as_enum :gender, {
    :male => 1,
    :female => 2
  }
  validates_as_enum :gender, :allow_nil => true
end

You will generally want integers, but strings are possible too:

create_table :users do |t|
  t.column :sex, :string
end

class User < ActiveRecord::Base
  acts_as_enum :gender, {
    :male => 'man',
    :female => 'woman'
  }
end

You may also add a suffix to the column name. In that case you won't be using the users.sex column but the users.sex_cd column (for instance). You will then be able to interact with User.sex (as symbols) and User.sex_enum (as integers):

create_table :users do |t|
  t.column :sex_cd, :integer
end

class User < ActiveRecord::Base
  acts_as_enum :gender, {
    :male => 1,
    :female => 2
  }, :suffix => 'enum'
end

Generated instance methods

user.gender = :male     # => :male
user.gender = 'female'  # => :female
user.gender = 1         # => :male

user.male?
user.female?

user.gender         # => :male
user.human_gender   # => "Male"

Generated class methods

User.genders        # => {:male => 1, :female => 2}
User.human_genders  # => [["Female", :female], ["Male", :male]]

Generated scopes

User.males          # => where(:gender => 0)
User.females        # => where(:gender => 1)

Views

<%= form_for user do |f| %>
  <%= f.select :gender, User.human_genders %>
<% end %>

I18n

It uses the following scope: "activerecord.enums.#{model_name.underscore}.genders". If not present it fallbacks to humanize.

Example:

fr:
  activerecord:
    enums:
      user:
        genders:
          male: Homme
          female: Femme

TODO

ActsAsEnum should not be tied to ActiveRecord but usable by any ActiveModel compliant ruby Object.