skip if DI is not in 3.2

Author: mykiwi

DependencyInjection/SwiftmailerExtension.php

@@ -72,14 +72,17 @@ protected function configureMailer($name, array $mailer, ContainerBuilder $conta
             ->setDefinition(sprintf('swiftmailer.mailer.%s.transport.eventdispatcher', $name), $definitionDecorator)
         ;
 
-        $options = array();
-        $envVariablesAllowed = array('transport', 'url', 'username', 'password', 'host', 'port', 'timeout', 'source_ip', 'local_domain', 'encryption', 'auth_mode');
-        foreach ($envVariablesAllowed as $key) {
-            $container->resolveEnvPlaceholders($mailer[$key], null, $userEnvs);
-            $options[$key] = $mailer[$key];
+        if (method_exists($container, 'resolveEnvPlaceholders')) {
+            $options = array();
+            $envVariablesAllowed = array('transport', 'url', 'username', 'password', 'host', 'port', 'timeout', 'source_ip', 'local_domain', 'encryption', 'auth_mode');
+            foreach ($envVariablesAllowed as $key) {
+                $container->resolveEnvPlaceholders($mailer[$key], null, $usedEnvs);
+                $options[$key] = $mailer[$key];
+            }
+        } else {
+            $usedEnvs = false;
         }
-
-        if ($userEnvs) {
+        if ($usedEnvs) {
             $transportId = sprintf('swiftmailer.mailer.%s.transport.dynamic', $name);
             $definitionDecorator = new Definition('\Swift_Transport');
             $definitionDecorator->setFactory(array('\Symfony\Bundle\SwiftmailerBundle\DependencyInjection\SwiftmailerTransportFactory', 'createTransport'));