Route Localize

Rails engine to translate routes using locale files and subdomains.

Only works with Rails 4.0. Check out route_translator for Rails 4.2 and Rails 5 compatibility.

In your Rails application's Gemfile add:

# Rails 4.0 engine to translate the routes
gem "route_localize"

Install the gem by running:

$ bundle

Route Localize adds two scopes you can use in your routes:

• localize: if your locale is the first parameter in the path. For example http://example.com/en/foo.
• localize_subdomain: if your locale is your subdomain. For example http://en.example.com/foo.

In your config/routes.rb, add one of the scopes around your routes. For example:

scope localize: [:en, :fr] do
  get 'trees/new', to: 'trees#new'
end
root 'pages#index'

Then, create a config/locales/routes.yml with translations for each part of your routes under the routes key. For example:

fr:
  routes:
    trees: arbres
    new: nouveau

With this example you would have the following routes defined:

        Prefix Verb URI Pattern               Controller#Action
  trees_new_en GET /trees/new(.:format)      trees#new {:subdomain=>:en}
  trees_new_fr GET /arbres/nouveau(.:format) trees#new {:subdomain=>:fr}

You also get the trees_new_path and trees_new_url helpers that will call trees_new_en or trees_new_fr depending on the current locale.

If you want to be able to switch to the current page in another language add the following inside your app/helpers/application_helper.rb:

module ApplicationHelper
  include RouteLocalizeHelper
end

You can then use the locale_switch_url or locale_switch_subdomain_url helpers in your views like so:

<%= link_to "Version française", locale_switch_url("fr") %>
<%= link_to "English version", locale_switch_url("en") %>

If some of your params are different depending on the language, you can override the switcher's params by creating a route_localize_options method that takes the locale as a parameter.

For example if you would like to switch from http://en.example.org/products/keyboard to http://fr.example.org/produits/clavier, where keyboard and clavier are the :id parameter in your routes.

In this case you might already have something like this in controller:

class ProductsController < ApplicationController
  def show
    if I18n.locale == :fr
      @tree = Product.find_by_name_fr(params[:id])
    else
      @tree = Product.find_by_name_en(params[:id])
    end
  end
end

In this case you would need to add the route_localize_path_options method that returns a hash of params to change depending on the locale. Here, :id needs to be different because we are looking at two different database fields.

  helper_method :route_localize_path_options
  def route_localize_path_options(locale)
    {
      id: (locale == "fr" ? @tree.name_fr : @tree.name_en)
    }
  end

Because Rails' url_for cannot find the translation url automatically, prefer to use the _path and _url helpers instead.

If you can't, one way around is to use RouteLocalize.translate_path.

For example :

RouteLocalize.translate_path(url_for(controller: 'trees', action: 'index'),
                             I18n.locale)

If you are using subdomains you should add the by_subdomain: true option to translate_path.

You may help by submitting issues, creating pull requests, talking about the gem or by saying thanks.

The following gems could also be a good match for your project:

• translate_routes
• route_translator
• rails-translate-routes
• routing-filter

Route Localize is different from these solutions because it:

• can add a constraint to the subdomain instead of relying on the locale beeing in the url (en/… fr/)
• plays well with gems that introduce extra locales, routes you don't want to translate, or reload routes before i18n is loaded (activeadmin for example)
• includes a language switcher helper that returns the correct url in every other language

By Sunny Ripert, Licensed under the MIT.