Rails: How to use i18n with Rails 4 enums

Question

Rails 4 Active Record Enums are great, but what is the right pattern for translating with i18n?

Answer 1

Combining the answers from Repolês and Aliaksandr, for Rails 5, we can build 2 methods that allow you to translate a single value or a collection of values from an enum attribute.

Set up the translations in your .yml file:

en:
  activerecord:
    attributes:
      user:
        statuses:
          active: "Active"
          pending: "Pending"
          archived: "Archived"

In the ApplicationRecord class, from which all models inherit, we define a method that handles translations for a single value and another one that handles arrays by calling it:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  def self.translate_enum_name(enum_name, enum_value)
    I18n.t("activerecord.attributes.#{model_name.i18n_key}.#{enum_name.to_s.pluralize}.#{enum_value}")
  end

  def self.translate_enum_collection(enum_name)
    enum_values = self.send(enum_name.to_s.pluralize).keys
    enum_values.map do |enum_value|
      self.translate_enum_name enum_name, enum_value
    end
  end
end 

In our views, we can then translate single values:

<p>User Status: <%= User.translate_enum_name :status, @user.status %></p>

Or the entire collection of enum values:

<%= f.select(:status, User.translate_enum_collection :status) %>

Answer 2

I've created a gem for this.

http://rubygems.org/gems/translated_attribute_value

Add to your gemfile:

gem 'translated_attribute_value'

If you have a status field for user:

pt-BR:
  activerecord:
    attributes:
      user:
        status_translation:
          value1: 'Translation for value1'
          value2: 'Translation for value2'

And in your view you can call like this:

user.status_translated

It works with active record, mongoid or any other class with getter/setters:

https://github.com/viniciusoyama/translated_attribute_value

Answer 3

Yet another way, I find it a bit more convenient using a concern in models

Concern :

module EnumTranslation
  extend ActiveSupport::Concern

  def t_enum(enum)
    I18n.t "activerecord.attributes.#{self.class.name.underscore}.enums.#{enum}.#{self.send(enum)}"
  end
end

YML:

fr:
    activerecord:
      attributes:
        campaign:
          title: Titre
          short_description: Description courte
          enums:
            status:
              failed: "Echec"

View :

<% @campaigns.each do |c| %>
  <%= c.t_enum("status") %>
<% end %>

Don't forget to add concern in your model :

class Campaign < ActiveRecord::Base
  include EnumTranslation

  enum status: [:designed, :created, :active, :failed, :success]
end

Answer 4

You can simply add a helper:

def my_something_list
  modes = 'activerecord.attributes.mymodel.my_somethings'
  I18n.t(modes).map {|k, v| [v, k]}
end

and set it up as usually:

en:
  activerecord:
    attributes:
      mymodel:
        my_somethings:
           my_enum_value: "My enum Value!"

then use it with your select: my_something_list

Answer 5

Starting from Rails 5, all models will inherit from ApplicationRecord.

class User < ApplicationRecord
  enum status: [:active, :pending, :archived]
end

I use this superclass to implement a generic solution for translating enums:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  def self.human_enum_name(enum_name, enum_value)
    I18n.t("activerecord.attributes.#{model_name.i18n_key}.#{enum_name.to_s.pluralize}.#{enum_value}")
  end
end

Then I add the translations in my .yml file:

en:
  activerecord:
    attributes:
      user:
        statuses:
          active: "Active"
          pending: "Pending"
          archived: "Archived"

Finally, to get the translation I use:

User.human_enum_name(:status, :pending)
=> "Pending"

Answer 6

The model:

class User < ActiveRecord::Base
  enum role: [:master, :apprentice]
end

The locale file:

en:
  activerecord:
    attributes:
      user:
        master: Master
        apprentice: Apprentice

Usage:

User.human_attribute_name(:master) # => Master
User.human_attribute_name(:apprentice) # => Apprentice