added available_locales (returns an array of locales for which transl…

…ations are available)

lib/i18n.rb

@@ -45,6 +45,11 @@ def locale=(locale)
       Thread.current[:locale] = locale
     end
 
+    # Returns an array of locales for which translations are available
+    def available_locales
+      backend.available_locales
+    end
+
     # Sets the exception handler.
     def exception_handler=(exception_handler)
       @@exception_handler = exception_handler

lib/i18n/backend/simple.rb

@@ -69,6 +69,12 @@ def initialized?
         @initialized ||= false
       end
 
+      # Returns an array of locales for which translations are available
+      def available_locales
+        init_translations unless initialized?
+        translations.keys
+      end
+
       def reload!
         @initialized = false
         @translations = nil

test/simple_backend_test.rb

@@ -124,6 +124,16 @@ def test_store_translations_converts_keys_to_symbols
   end
 end
 
+class I18nSimpleBackendAvailableLocalesTest < Test::Unit::TestCase
+  def test_available_locales
+    @backend = I18n::Backend::Simple.new
+    @backend.store_translations 'de', :foo => 'bar'
+    @backend.store_translations 'en', :foo => 'foo'
+
+    assert_equal ['de', 'en'], @backend.available_locales.map{|locale| locale.to_s }.sort
+  end
+end
+
 class I18nSimpleBackendTranslateTest < Test::Unit::TestCase
   include I18nSimpleBackendTestSetup