made translator.domains and translator.messages optional

doc/providers/translation.rst

@@ -7,10 +7,10 @@ application into different languages.
 Parameters
 ----------
 
-* **translator.messages**: A mapping of locales to message arrays. This
-  parameter contains the translation data in all languages.
+* **translator.messages** (optional): A mapping of locales to message arrays.
+  This parameter contains the translation data in all languages.
 
-* **translator.domains**: Same as above but stored by domains.
+* **translator.domains** (optional): Same as above but stored by domains.
 
 * **locale** (optional): The locale for the translator. You will most likely
   want to set this based on some request parameter. Defaults to ``en``.

src/Silex/Provider/TranslationServiceProvider.php

@@ -35,15 +35,20 @@ class TranslationServiceProvider implements ServiceProviderInterface
             }
 
             $translator->addLoader('array', $app['translator.loader']);
+
+            if (isset($app['translator.messages'])) {
                 foreach ($app['translator.messages'] as $locale => $messages) {
                     $translator->addResource('array', $messages, $locale);
                 }
+            }
 
+            if (isset($app['translator.domains'])) {
                 foreach ($app['translator.domains'] as $domain => $data) {
                     foreach ($data as $locale => $messages) {
                         $translator->addResource('array', $messages, $locale, $domain);
                     }
                 }
+            }
 
             return $translator;
         });