[Translation] Added logging capability to translator

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -585,6 +585,15 @@ private function registerTranslatorConfiguration(array $config, ContainerBuilder
         }
         $translator->addMethodCall('setFallbackLocales', array($config['fallback']));
 
+        // Inject logger into translation
+        if ($container->getParameter('kernel.debug')) {
+            $logger = new Reference('logger', ContainerInterface::IGNORE_ON_INVALID_REFERENCE);
+
+            $translator
+                ->addTag('monolog.logger', array('channel' => 'translation'))
+                ->addMethodCall('setLogger', array($logger));
+        }
+
         // Discover translation directories
         $dirs = array();
         if (class_exists('Symfony\Component\Validator\Validator')) {

src/Symfony/Component/Translation/CHANGELOG.md

@@ -1,6 +1,10 @@
 CHANGELOG
 =========
 
+2.5.0
+-----
+ * added logging capabilities to translator.
+
 2.3.0
 -----
 

src/Symfony/Component/Translation/Tests/TranslatorTest.php

@@ -287,6 +287,43 @@ public function testTransChoiceFallbackWithNoTranslation()
         // unchanged if it can't be found
         $this->assertEquals('some_message2', $translator->transChoice('some_message2', 10, array('%count%' => 10)));
     }
+
+    public function testTransWithNoTranslationIsLogged()
+    {
+        if (!interface_exists('Psr\Log\LoggerInterface')) {
+            $this->markTestSkipped('The "LoggerInterface" is not available');
+        }
+
+        $logger = $this->getMock('Psr\Log\LoggerInterface');
+        $logger->expects($this->once())
+            ->method('warning')
+            ->with('Translation not found.')
+        ;
+
+        $translator = new Translator('ar');
+        $translator->setLogger($logger);
+        $translator->trans('bar');
+    }
+
+    public function testTransChoiceFallbackIsLogged()
+    {
+        if (!interface_exists('Psr\Log\LoggerInterface')) {
+            $this->markTestSkipped('The "LoggerInterface" is not available');
+        }
+
+        $logger = $this->getMock('Psr\Log\LoggerInterface');
+        $logger->expects($this->once())
+            ->method('debug')
+            ->with('Translation use fallback catalogue.')
+        ;
+
+        $translator = new Translator('ar');
+        $translator->setLogger($logger);
+        $translator->setFallbackLocales(array('en'));
+        $translator->addLoader('array', new ArrayLoader());
+        $translator->addResource('array', array('some_message2' => 'one thing|%count% things'), 'en');
+        $translator->transChoice('some_message2', 10, array('%count%' => 10));
+    }
 }
 
 class String

src/Symfony/Component/Translation/Translator.php

@@ -13,6 +13,7 @@
 
 use Symfony\Component\Translation\Loader\LoaderInterface;
 use Symfony\Component\Translation\Exception\NotFoundResourceException;
+use Psr\Log\LoggerInterface;
 
 /**
  * Translator.
@@ -53,6 +54,11 @@ class Translator implements TranslatorInterface
      */
     private $selector;
 
+    /**
+     * @var LoggerInterface|null
+     */
+    private $logger;
+
     /**
      * Constructor.
      *
@@ -185,6 +191,8 @@ public function trans($id, array $parameters = array(), $domain = null, $locale
             $this->loadCatalogue($locale);
         }
 
+        $this->log($this->catalogues[$locale], $id, $domain);
+
         return strtr($this->catalogues[$locale]->get((string) $id, $domain), $parameters);
     }
 
@@ -210,6 +218,9 @@ public function transChoice($id, $number, array $parameters = array(), $domain =
         $id = (string) $id;
 
         $catalogue = $this->catalogues[$locale];
+
+        $this->log($catalogue, $id, $domain);
+
         while (!$catalogue->defines($id, $domain)) {
             if ($cat = $catalogue->getFallbackCatalogue()) {
                 $catalogue = $cat;
@@ -222,6 +233,16 @@ public function transChoice($id, $number, array $parameters = array(), $domain =
         return strtr($this->selector->choose($catalogue->get($id, $domain), (int) $number, $locale), $parameters);
     }
 
+    /**
+     * Sets the logger.
+     *
+     * @param LoggerInterface $logger A logger instance
+     */
+    public function setLogger(LoggerInterface $logger)
+    {
+        $this->logger = $logger;
+    }
+
     /**
      * Gets the loaders.
      *
@@ -244,6 +265,26 @@ protected function loadCatalogue($locale)
         $this->loadFallbackCatalogues($locale);
     }
 
+    /**
+     * Logs for missing catalogue.
+     *
+     * @param MessageCatalogueInterface $catalogue
+     * @param string                    $id
+     * @param string                    $domain
+     */
+    private function log(MessageCatalogueInterface $catalogue, $id, $domain)
+    {
+        if (null === $this->logger || $catalogue->defines($id, $domain)) {
+            return;
+        }
+
+        if ($catalogue->has($id, $domain)) {
+            $this->logger->debug('Translation use fallback catalogue.', array('id' => $id, 'domain' => $domain, 'locale' => $catalogue->getLocale()));
+        } else {
+            $this->logger->warning('Translation not found.', array('id' => $id, 'domain' => $domain, 'locale' => $catalogue->getLocale()));
+        }
+    }
+
     private function doLoadCatalogue($locale)
     {
         $this->catalogues[$locale] = new MessageCatalogue($locale);

src/Symfony/Component/Translation/composer.json

@@ -20,11 +20,13 @@
     },
     "require-dev": {
         "symfony/config": "~2.0",
-        "symfony/yaml": "~2.2"
+        "symfony/yaml": "~2.2",
+        "psr/log": "~1.0"
     },
     "suggest": {
         "symfony/config": "",
-        "symfony/yaml": ""
+        "symfony/yaml": "",
+        "psr/log": "For using logging capability in translator"
     },
     "autoload": {
         "psr-0": { "Symfony\\Component\\Translation\\": "" }