keram-refinery / globalize3

Globalize3

Globalize3 is the successor of Globalize for Rails and is targeted at ActiveRecord version 3.x. It is compatible with and builds on the new I18n API in Ruby on Rails and adds model translations to ActiveRecord.

Globalize3 is much more lightweight and compatible than its predecessor. Model translations in Globalize3 use default ActiveRecord features and no longer limit any ActiveRecord functionality.

Requirements

• ActiveRecord > 3.0.0
• I18n

Installation

To install Globalize3 with its default setup just use:

gem install globalize3

When using bundler put it in your Gemfile:

source 'https://rubygems.org'

gem 'globalize3'

Model translations

Model translations allow you to translate your models' attribute values. E.g.

class Post < ActiveRecord::Base
  translates :title, :text
end

Allows you to translate the attributes :title and :text per locale:

I18n.locale = :en
post.title # => Globalize3 rocks!

I18n.locale = :he
post.title # => גלובאלייז2 שולט!

In order to make this work, you'll need to add the appropriate translation tables. Globalize3 comes with a handy helper method to help you do this. It's called create_translation_table!. Here's an example:

Note that your migrations can use create_translation_table! and drop_translation_table! only inside the up and down instance methods, respectively. You cannot use create_translation_table! and drop_translation_table! inside the change instance method in Rails >= 3.1.0.

Rails 3.0

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.timestamps
    end
    Post.create_translation_table! :title => :string, :text => :text
  end
  def self.down
    drop_table :posts
    Post.drop_translation_table!
  end
end

Rails >= 3.1.0

Do not use the change method, use up and down!

class CreatePosts < ActiveRecord::Migration
  def up
    create_table :posts do |t|
      t.timestamps
    end
    Post.create_translation_table! :title => :string, :text => :text
  end
  def down
    drop_table :posts
    Post.drop_translation_table!
  end
end

Also, you can pass options for specific columns. Here’s an example:

class CreatePosts < ActiveRecord::Migration
  def up
    create_table :posts do |t|
      t.timestamps
    end
    Post.create_translation_table! :title => :string,
      :text => {:type => :text, :null => false, :default => 'abc'}
  end
  def down
    drop_table :posts
    Post.drop_translation_table!
  end
end

Note that the ActiveRecord model Post must already exist and have a translates directive listing the translated fields.

Migrating existing data to and from the translated version

As well as creating a translation table, you can also use create_translation_table! to migrate across any existing data to the default locale. This can also operate in reverse to restore any translations from the default locale back to the model when you don't want to use a translation table anymore using drop_translation_table!

This feature makes use of untranslated_attributes which allows access to the model's attributes as they were before the translation was applied. Here's an example (which assumes you already have a model called Post and its table exists):

class TranslatePosts < ActiveRecord::Migration
  def self.up
    Post.create_translation_table!({
      :title => :string,
      :text => :text
    }, {
      :migrate_data => true
    })
  end

  def self.down
    Post.drop_translation_table! :migrate_data => true
  end
end

Versioning with Globalize3

Globalize3 nicely integrates with paper_trail. To add versioning support to your model, you'll want to add the :versioning => true option to your call to translates. An example from our test suite:

translates :title, :content, :published, :published_at, :versioning => true

You will also need to have already generated the versions table that paper_trail expects. See the paper_trail README for more details.

If you are adding globalize3 to any previously versioned models, please note that you will need to add a new locale column to your versioning table.

Also, please see the tests in test/globalize3/versioning_test.rb for some current gotchas.

I18n fallbacks for empty translations

It is possible to enable fallbacks for empty translations. It will depend on the configuration setting you have set for I18n translations in your Rails config.

You can enable them by adding the next line to config/application.rb (or only config/environments/production.rb if you only want them in production)

config.i18n.fallbacks = true

By default, globalize3 will only use fallbacks when your translation model does not exist or the translation value for the item you've requested is nil. However it is possible to also use fallbacks for blank translations by adding :fallbacks_for_empty_translations => true to the translates method.

class Post < ActiveRecord::Base
  translates :title, :name
end

puts post.translations.inspect
# => [#<Post::Translation id: 1, post_id: 1, locale: "en", title: "Globalize3 rocks!", name: "Globalize3">,
      #<Post::Translation id: 2, post_id: 1, locale: "nl", title: '', name: nil>]

I18n.locale = :en
post.title # => 'Globalize3 rocks!'
post.name  # => 'Globalize3'

I18n.locale = :nl
post.title # => ''
post.name  # => 'Globalize3'

class Post < ActiveRecord::Base
  translates :title, :name, :fallbacks_for_empty_translations => true
end

puts post.translations.inspect
# => [#<Post::Translation id: 1, post_id: 1, locale: "en", title: "Globalize3 rocks!", name: "Globalize3">,
      #<Post::Translation id: 2, post_id: 1, locale: "nl", title: '', name: nil>]

I18n.locale = :en
post.title # => 'Globalize3 rocks!'
post.name  # => 'Globalize3'

I18n.locale = :nl
post.title # => 'Globalize3 rocks!'
post.name  # => 'Globalize3'

Fallback locales to each other

It is possible to setup locales to fallback to each other.

class Post < ActiveRecord::Base
  translates :title, :name
end

Globalize.fallbacks = {:en => [:en, :pl], :pl => [:pl, :en]}

I18n.locale = :en
en_post = Post.create(:title => 'en_title')

I18n.locale = :pl
pl_post = Post.create(:title => 'pl_title')
en_post.title # => 'en_title'

I18n.locale = :en
en_post.title # => 'en_title'
pl_post.title # => 'pl_title'

Scoping objects by those with translations

To only return objects that have a translation for the given locale we can use the with_translations scope. This will only return records that have a translations for the passed in locale.

Post.with_translations('en')
# => [
  #<Post::Translation id: 1, post_id: 1, locale: "en", title: "Globalize3 rocks!", name: "Globalize3">,
  #<Post::Translation id: 2, post_id: 1, locale: "nl", title: '', name: nil>
]

Post.with_translations(I18n.locale)
# => [
  #<Post::Translation id: 1, post_id: 1, locale: "en", title: "Globalize3 rocks!", name: "Globalize3">,
  #<Post::Translation id: 2, post_id: 1, locale: "nl", title: '', name: nil>
]

Post.with_translations('de')
# => []

Changes since Globalize2

• translation_table_name was renamed to translations_table_name
• available_locales has been removed. please use translated_locales

Migration from Globalize for Rails (version 1)

See this script by Tomasz Stachewicz: http://gist.github.com/120867

Alternative Solutions

• Veger's fork - uses default AR schema for the default locale, delegates to the translations table for other locales only
• TranslatableColumns - have multiple languages of the same attribute in a model (Iain Hecker)
• Traco - A newer take on using multiple columns in the same model (Barsoom)
• localized_record - allows records to have localized attributes without any modifications to the database (Glenn Powell)
• model_translations - Minimal implementation of Globalize2 style model translations (Jan Andersson)
• hstore_translate - Rails I18n library for ActiveRecord model/data translation using PostgreSQL's hstore datatype (Rob Worley)

Related solutions

• globalize2_versioning - acts_as_versioned style versioning for globalize2 (Joshua Harvey)
• i18n_multi_locales_validations - multi-locales attributes validations to validates attributes from globalize2 translations models (Sébastien Grosjean)
• globalize2 Demo App - demo application for globalize2 (Sven Fuchs)
• migrate_from_globalize1 - migrate model translations from Globalize1 to globalize2 (Tomasz Stachewicz)
• easy_globalize2_accessors - easily access (read and write) globalize2-translated fields (astropanic, Tomasz Stachewicz)
• globalize2-easy-translate - adds methods to easily access or set translated attributes to your model (bsamman)
• batch_translations - allow saving multiple globalize2 translations in the same request (Jose Alvarez Rilla)