Update multiple services example

This PR propose to replace SwiftMailer with the Mailer component and to add the Logger service for a better understanding how to inject multiple services

Author: ker0x

service_container.rst

@@ -295,34 +295,46 @@ made. To do that, you create a new class::
     namespace App\Updates;
 
     use App\Service\MessageGenerator;
+    use Psr\Log\LoggerInterface;
+    use Symfony\Component\Mailer\MailerInterface;
+    use Symfony\Component\Mime\Email;
 
     class SiteUpdateManager
     {
         private $messageGenerator;
         private $mailer;
+        private $logger;
 
-        public function __construct(MessageGenerator $messageGenerator, \Swift_Mailer $mailer)
+        public function __construct(MessageGenerator $messageGenerator, MailerInterface $mailer, LoggerInterface $logger)
         {
             $this->messageGenerator = $messageGenerator;
             $this->mailer = $mailer;
+            $this-logger = $logger;
         }
 
-        public function notifyOfSiteUpdate()
+        public function notifyOfSiteUpdate(): bool
         {
             $happyMessage = $this->messageGenerator->getHappyMessage();
 
-            $message = (new \Swift_Message('Site update just happened!'))
-                ->setFrom('admin@example.com')
-                ->setTo('manager@example.com')
-                ->addPart(
-                    'Someone just updated the site. We told them: '.$happyMessage
-                );
+            try {
+                $email = (new Email())
+                    ->from('admin@example.com')
+                    ->to('manager@example.com')
+                    ->subject('Site update just happened!')
+                    ->text('Someone just updated the site. We told them: '.$happyMessage);
 
-            return $this->mailer->send($message) > 0;
+                $this->mailer->send($email);
+
+                return true;
+            } catch (\Exception $exception) {
+                $this->logger->error($exception->getMessage());
+
+                return false;
+            }
         }
     }
 
-This needs the ``MessageGenerator`` *and* the ``Swift_Mailer`` service. That's no
+This needs the ``MessageGenerator`` *and* both ``Mailer`` and ``Logger`` services. That's no
 problem! In fact, this new service is ready to be used. In a controller, for example,
 you can type-hint the new ``SiteUpdateManager`` class and use it::