Fix optional cache warmers are always instantiated whereas they should be lazy-loaded

Author: romainneutron

CacheWarmer/TranslationsCacheWarmer.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Bundle\FrameworkBundle\CacheWarmer;
 
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpKernel\CacheWarmer\CacheWarmerInterface;
 use Symfony\Component\HttpKernel\CacheWarmer\WarmableInterface;
 use Symfony\Component\Translation\TranslatorInterface;
@@ -22,18 +23,35 @@
  */
 class TranslationsCacheWarmer implements CacheWarmerInterface
 {
+    private $container;
     private $translator;
 
-    public function __construct(TranslatorInterface $translator)
+    /**
+     * TranslationsCacheWarmer constructor.
+     *
+     * @param ContainerInterface|TranslatorInterface $container
+     */
+    public function __construct($container)
     {
-        $this->translator = $translator;
+        // As this cache warmer is optional, dependencies should be lazy-loaded, that's why a container should be injected.
+        if ($container instanceof ContainerInterface) {
+            $this->container = $container;
+        } elseif ($container instanceof TranslatorInterface) {
+            $this->translator = $container;
+        } else {
+            throw new \InvalidArgumentException(sprintf('%s only accepts instance of Symfony\Component\DependencyInjection\ContainerInterface or Symfony\Component\Translation\TranslatorInterface as first argument.', __CLASS__));
+        }
     }
 
     /**
      * {@inheritdoc}
      */
     public function warmUp($cacheDir)
     {
+        if (null === $this->translator) {
+            $this->translator = $this->container->get('translator');
+        }
+
         if ($this->translator instanceof WarmableInterface) {
             $this->translator->warmUp($cacheDir);
         }

Resources/config/translation.xml

@@ -159,7 +159,7 @@
         <service id="translation.writer" class="%translation.writer.class%"/>
 
         <service id="translation.warmer" class="Symfony\Bundle\FrameworkBundle\CacheWarmer\TranslationsCacheWarmer" public="false">
-            <argument type="service" id="translator" />
+            <argument type="service" id="service_container" />
             <tag name="kernel.cache_warmer" />
         </service>
     </services>