Only prepend locales to paths when there's more than one locale to choose from.

Replaces core "locale" filter with customised one.  Fixes #82

4 files changed, 37 insertions, 2 deletions

diff --git a/config/environment.rb b/config/environment.rb
index 86c66ad18..ec6a4096f 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -82,6 +82,10 @@ Rails::Initializer.run do |config|
   # Make Active Record use UTC-base instead of local time
   config.active_record.default_timezone = :utc
   
+  config.after_initialize do    
+     require 'routing_filters.rb'
+  end
+
   # See Rails::Configuration for more options
   ENV['RECAPTCHA_PUBLIC_KEY'] = MySociety::Config::get("RECAPTCHA_PUBLIC_KEY", 'x');
   ENV['RECAPTCHA_PRIVATE_KEY'] = MySociety::Config::get("RECAPTCHA_PRIVATE_KEY", 'x');
diff --git a/config/routes.rb b/config/routes.rb
index 175a37a82..9765b26b8 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -195,8 +195,7 @@ ActionController::Routing::Routes.draw do |map|
         rule.admin_rule_update '/admin/censor/update', :action => 'update'
         rule.admin_rule_destroy '/admin/censor/destroy/:censor_rule_id', :action => 'destroy'
     end
-    map.filter('locale')
-
+    map.filter('conditionallyprependlocale')
 
     # Allow downloading Web Service WSDL as a file with an extension
     # instead of a file named 'wsdl'
diff --git a/lib/routing_filters.rb b/lib/routing_filters.rb
new file mode 100644
index 000000000..cdb58e7c1
--- /dev/null
+++ b/lib/routing_filters.rb
@@ -0,0 +1,9 @@
+module RoutingFilter
+  class Conditionallyprependlocale < RoutingFilter::Locale
+      # Override core Locale filter not to prepend locale path segment
+      # when there's only one locale
+      def prepend_locale?(locale)
+        locale && I18n.available_locales.length > 1 && (self.class.include_default_locale? || !default_locale?(locale))
+      end
+  end
+end
diff --git a/spec/controllers/general_controller_spec.rb b/spec/controllers/general_controller_spec.rb
index 6a48f142a..7807a5541 100644
--- a/spec/controllers/general_controller_spec.rb
+++ b/spec/controllers/general_controller_spec.rb
@@ -22,6 +22,29 @@ describe GeneralController, "when searching" do
         response.should redirect_to(:action => 'search', :combined => "mouse") # URL /search/:query
     end
 
+    describe "when using different locale settings" do 
+        home_link_regex = /href=".*\/en"/
+        it "should generate URLs with a locale prepended when there's more than one locale set" do
+            ActionController::Routing::Routes.add_filters(['conditionallyprependlocale'])
+            get :frontpage
+            response.should have_text(home_link_regex)
+        end
+
+        it "should generate URLs without a locale prepended when there's only one locale set" do
+            ActionController::Routing::Routes.add_filters(['conditionallyprependlocale'])
+            old_available_locales =  FastGettext.default_available_locales
+            available_locales = ['en']
+            FastGettext.default_available_locales = available_locales
+            I18n.available_locales = available_locales
+
+            get :frontpage
+            response.should_not have_text(home_link_regex)
+
+            FastGettext.default_available_locales = old_available_locales
+            I18n.available_locales = old_available_locales
+        end
+    end
+
     describe 'when using xapian search' do
 
       # rebuild xapian index after fixtures loaded