Examples of advanced Rails Routes

routes.rb

Rails.application.routes.draw do

  get '/(:locale)/products/(:category)/(page/:page).:extension',
        :to => 'products#index',
        :as => :products,
        :constraints => {
          :locale => /[a-z]{2}/,
          :category => /.+?/,
          :page => /\d+/
        },
        :defaults => {
          :page => 1,
          :extension => 'html',
          :locale => 'en'
        }

  # products_path(:page => 1)
  # => /products.html

  # products_path(:page => 2)
  # => /products/page/2.html

  # products_path(:page => 2, :locale => 'de')
  # => /de/products/page/2.html

  # products_path('computers', :page => 2, :locale => 'de')
  # => /de/products/computers/page/2.html

  # products_path('computers/apple', :page => 2, :locale => 'de')
  # => /de/products/computers/apple/page/2.html

  # products_path('computers/apple')
  # => /products/computers/apple.html

end


Please use this in you routes.rb:

   scope "(/:locale)" do
     resources :items
   end

and in your application controller:

class ApplicationController < ActionController::Base
   protect_from_forgery

   before_filter :set_locale
   def set_locale
     I18n.locale = params[:locale]
   end

   def default_url_options(options={})
     {:locale => I18n.locale}
   end
end

config/application.rb:
config.i18n.default_locale = :de