Rails production: locales switching - ruby-on-rails

Question

In my app I've made switching locales with sessions. The logic keeps in controller:
class SetLanguageController < ApplicationController
def russian
I18n.locale = :ru
set_session_and_redirect
end
def english
I18n.locale = :en
set_session_and_redirect
end
private
def set_session_and_redirect
session[:locale] = I18n.locale
redirect_to :back
rescue ActionController::RedirectBackError
redirect_to :root
end
end
switching works with links:
link_to_unless I18n.locale == :ru, "Русский", rus_locale_path
link_to_unless I18n.locale == :en, "English", eng_locale_path
code for locales in routes (unnecessary for question, but if you interesting)
get 'rus_locale' => 'set_language#russian'
get 'eng_locale' => 'set_language#english'
It works in development perfectly, but on production
application.rb
config.i18n.load_path += Dir[Rails.root.join('config','locales', '*.yml').to_s]
config.i18n.default_locale = :ru
How can I make it working on production? Thanks

Answer 1

I solved problem with setting a before_filter in application controller like
before_filter :set_locale
def set_locale
I18n.locale = session[:locale] ? session[:locale] : I18n.default_locale
end
But this solution is dummy because it doesn't solve essence of problem actually - previous code worked in development, but in production. If you know how to fix it more smartly you are wellcome

Answer 2

Robust I18n implementation:
Add a locales.rb initializer to define what I18n.available_locales you support:
# config/initializers/locales.rb
# Permitted locales available for the application
I18n.available_locales = [:en, :fr]
Set a language_name value in each language's locale file (e.g. fr.yml):
fr:
language_name: "Français"
As you add more languages, this ERB will let you generically switch between them:
// app/views/layouts/_languages.html.erb
<span class="languages">
<% I18n.available_locales.each do |locale| %>
<% if I18n.locale == locale %>
<%= link_to I18n.t('language_name', locale: locale), url_for( params.clone.permit!.merge(locale: locale, only_path: true ), {style: "display:none" } %>
<% else %>
<%= link_to I18n.t('language_name', locale: locale), url_for( params.clone.permit!.merge(locale: locale, only_path: true ) %>
<% end %>
<% end %>
</span>
For the controller, we automatically find the correct language for the user by detecting their browser's Accept-Language HTTP header (using the http_accept_language gem).
Set a session cookie to preserve locale across requests.
Or optionally, use default_url_options to insert the ?locale= param into your app's url. I do both.
Controller:
class ApplicationController < ActionController::Base
before_action :set_locale
private
def set_locale
I18n.locale = begin
extract_locale ||
session[:locale] ||
http_accept_language.compatible_language_from(I18n.available_locales) ||
I18n.default_locale
end
session[:locale] = I18n.locale
end
def extract_locale
parsed_locale = params[:locale].dup
I18n.available_locales.map(&:to_s).include?(parsed_locale) ? parsed_locale : nil
end
def default_url_options
{ locale: I18n.locale }
end
end