minor #15289 [EventDispatcher] Minor fixes (sebpacz)

This PR was merged into the 4.4 branch.

Discussion
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[EventDispatcher] Minor fixes

I have added some minor fixes to the Event Dispatcher pages.

Commits
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e0b2746 [EventDispatcher] Minor fixes

Author: javiereguiluz

components/event_dispatcher/generic_event.rst

@@ -80,7 +80,7 @@ access the event arguments::
     {
         public function handler(GenericEvent $event)
         {
-            if (isset($event['type']) && $event['type'] === 'foo') {
+            if (isset($event['type']) && 'foo' === $event['type']) {
                 // ... do something
             }
 

event_dispatcher/before_after_filters.rst

@@ -189,7 +189,7 @@ serve as a basic flag that this request underwent token authentication::
     {
         // ...
 
-        if ($controller[0] instanceof TokenAuthenticatedController) {
+        if ($controller instanceof TokenAuthenticatedController) {
             $token = $event->getRequest()->query->get('token');
             if (!in_array($token, $this->tokens)) {
                 throw new AccessDeniedHttpException('This action needs a valid token!');

event_dispatcher/method_behavior.rst

@@ -21,7 +21,7 @@ end of the method::
             $event = new BeforeSendMailEvent($subject, $message);
             $this->dispatcher->dispatch($event, 'mailer.pre_send');
 
-            // get $foo and $bar from the event, they may have been modified
+            // get $subject and $message from the event, they may have been modified
             $subject = $event->getSubject();
             $message = $event->getMessage();
 
@@ -134,7 +134,7 @@ could listen to the ``mailer.post_send`` event and change the method's return va
         public static function getSubscribedEvents()
         {
             return [
-                'mailer.post_send' => 'onMailerPostSend'
+                'mailer.post_send' => 'onMailerPostSend',
             ];
         }
     }