adds i18n support to routes and application controller; default_locale is set to :en

app/controllers/application_controller.rb

@@ -1,10 +1,13 @@
 # encoding: utf-8
 class ApplicationController < ActionController::Base
+  include Foodsoft::ControllerExtensions::Locale
+  helper_method :available_locales
 
   protect_from_forgery
-  before_filter :select_language, :select_foodcoop, :authenticate, :store_controller, :items_per_page, :set_redirect_to
+  before_filter  :select_foodcoop, :authenticate, :store_controller, :items_per_page, :set_redirect_to
   after_filter  :remove_controller
 
+  
   # Returns the controller handling the current request.
   def self.current
     Thread.current[:application_controller]
@@ -142,8 +145,4 @@ class ApplicationController < ActionController::Base
     {foodcoop: FoodsoftConfig.scope}
   end
   
-  # Used to prevent accidently switching to :en in production mode.
-  def select_language
-    I18n.locale = :de
-  end
 end

config/application.rb

@@ -31,7 +31,7 @@ module Foodsoft
 
     # Internationalization.
     config.i18n.load_path += Dir[Rails.root.join('config', 'locales', '**', '*.{rb,yml}')]
-    config.i18n.default_locale = :de
+    config.i18n.default_locale = :en
 
     # Configure the default encoding used in templates for Ruby 1.9.
     config.encoding = "utf-8"

config/routes.rb

@@ -8,6 +8,8 @@ Foodsoft::Application.routes.draw do
 
   root :to => redirect("/#{FoodsoftConfig.scope}")
 
+  constraints(locale: /[a-z]{2}/) do
+    scope "(:locale)" do
       scope '/:foodcoop' do
       
         # Root path
@@ -187,4 +189,6 @@ Foodsoft::Application.routes.draw do
         match ':controller(/:action(/:id))(.:format)'
       
       end # End of /:foodcoop scope
+    end #  End of /:locale scope
+  end # End of :locale constraints
 end

lib/foodsoft/controller_extensions.rb

@@ -0,0 +1,52 @@
+# -*- encoding : utf-8 -*-
+module Foodsoft
+  module ControllerExtensions
+    module Locale
+      extend ActiveSupport::Concern
+
+      included do
+        before_filter :set_locale
+      end
+
+      module InstanceMethods
+        def explicitly_requested_language
+          params[:locale]
+        end
+
+        def session_language
+          session[:locale]
+        end
+
+        def browser_language
+          request.env['HTTP_ACCEPT_LANGUAGE'] ? request.env['HTTP_ACCEPT_LANGUAGE'].scan(/^[a-z]{2}/).first : nil
+        end
+
+        def default_language
+          ::I18n.default_locale
+        end
+
+        protected
+
+        def select_language_according_to_priority
+          explicitly_requested_language || session_language || browser_language
+        end
+
+        def available_locales
+          ::I18n.available_locales
+        end
+
+        def set_locale
+          if available_locales.include?(select_language_according_to_priority)
+            ::I18n.locale = select_language_according_to_priority
+          else
+            ::I18n.locale = default_language
+          end
+          
+          locale = session[:locale] = ::I18n.locale
+          logger.info("Set locale to #{locale}")
+        end
+      end
+
+    end
+  end
+end