This simple plugin creates translations for your model. Uses delegation pattern: http://en.wikipedia.org/wiki/Delegation_pattern

Tested with ActiveRecord versions: 2.3.5, 2.3.9, 3.0.0, 3.1.0 (to test with Rails 3.1 run rake RAILS_VERSION=3.1) And tested with ruby 1.8.7 and 1.9.2

gem install has_translations

or as a plugin

script/plugin install git://github.com/dmitry/has_translations.git

For example you have Article model and you want to have title and text to be translated.

Create model named ArticleTranslation (Rule: [CamelCaseModelName]Translation)

Migration should have locale as a string with two letters and belongs_to associative id, like:

class CreateArticleTranslations < ActiveRecord::Migration
  def self.up
    create_table :article_translations do |t|
      t.integer :article_id, :null => false
      t.string :locale, :null => false, :limit => 2
      t.string :title, :null => false
      t.text :text, :null => false
    end

    add_index :article_translations, [:article_id, :locale], :unique => true
  end

  def self.down
    drop_table :article_translations
  end
end

Add to article model translations :value1, :value2:

class Article < ActiveRecord::Base
  translations :title, :text
end

And that's it. Now you can add your translations using:

article = Article.create

article.translations.create(:locale => 'en', :title => 'title', :text => 'text') # or ArticleTranslation.create(:article => article, :locale => 'en', :title => 'title', :text => 'text')
article.translations.create(:locale => 'ru', :title => 'заголовок', :text => 'текст')
article.reload # reload cached translations association array
I18n.locale = :en
article.text # text
I18n.locale = :ru
article.title # заголовок

You can use text filtering plugins, like acts_as_sanitiled and validations, and anything else that is available to the ActiveRecord:

class ArticleTranslation < ActiveRecord::Base
  acts_as_sanitiled :title, :text

  validates_presence_of :title, :text
  validates_length_of :title, :maximum => 100
end

Options:

• :fallback => true [default: false] - fallback 1) default locale; 2) first from translations;
• :reader => false [default: true] - add reader to the model object
• :writer => true [default: false] - add writer to the model object
• :autosave => true [default: false] - use autosave option for the ActiveRecord translations relation
• :nil => nil [default: ''] - if no model found by default returns empty string, you can set it for example to nil (no lambda supported)

It's better to use translations with accepts_nested_attributes_for:

accepts_nested_attributes_for :translations

To create a form for this you can use all_translations method. It's have all the locales that you have added using the I18n.available_locales= method. If translation for one of the locale isn't exists, it will build it with :locale. So an example which I used in the production (using formtastic gem):

<% semantic_form_for [:admin, @article] do |f| %>
  <%= f.error_messages %>

  <% f.inputs :name => "Basic" do %>
    <% object.all_translations.values.each do |translation| %>
      <% f.semantic_fields_for :translations, translation do |ft| %>
        <%= ft.input :title, :label => "Title #{ft.object.locale.to_s.upcase}" %>
        <%= ft.input :text, :label => "Text #{ft.object.locale.to_s.upcase}" %>
        <%= ft.input :locale, :as => :hidden %>
      <% end %>
    <% end %>
  <% end %>
<% end %>

Sometimes you have validations in the translation model, and if you want to skip the translations that you don't want to add to the database, you can use :reject_if option, which is available for the accepts_nested_attributes_for:

accepts_nested_attributes_for :translations, :reject_if => lambda { |attrs| attrs['title'].blank? && attrs['text'].blank? }

named_scope translated(locale) - with that named_scope you can find only those models that is translated only to specific locale. For example if you will have 2 models, one is translated to english and the second one isn't, then it Article.translated(:en) will find only first one.

I suggest you to use latest i18n gem, include it in your rails 2 environment:

config.gem 'i18n', :version => '0.4.1' # change version to the latest

• add installation description to readme
• model and migration generators
• caching
• write more examples: fallback feature
• write blog post about comparison and benefits of this plugin between another translation model plugins

I know three of them:

• puret - special for Rails 3 and almost the same as this project.
• globalite2 - a lot of magic.
• model_translations - almost the same as this project, but more with more code in lib.
• translatable_columns - different approach: every column have own postfix "_#{locale}" in the same table (sometimes it could be fine).

noch.es, eten.es, sem.ee

Copyright (c) 2009-2010 [Dmitry Polushkin], released under the MIT license