From fa5b7eb95b2889c34533c00942aeadcd07322af9 Mon Sep 17 00:00:00 2001
From: Roland Franssen <franssen.roland@gmail.com>
Date: Sat, 2 Dec 2017 18:24:36 +0100
Subject: [PATCH] [DI] Allow for invokable event listeners

---
 .../Component/EventDispatcher/CHANGELOG.md    |  5 ++
 .../RegisterListenersPass.php                 |  4 ++
 .../RegisterListenersPassTest.php             | 52 +++++++++++++++++++
 3 files changed, 61 insertions(+)

diff --git a/src/Symfony/Component/EventDispatcher/CHANGELOG.md b/src/Symfony/Component/EventDispatcher/CHANGELOG.md
index e570303e742cc..cd54acaaecdb3 100644
--- a/src/Symfony/Component/EventDispatcher/CHANGELOG.md
+++ b/src/Symfony/Component/EventDispatcher/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.1.0
+-----
+
+ * added support for invokable event listeners tagged with `kernel.event_listener` by default 
+
 4.0.0
 -----
 
diff --git a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
index 210ef972386a2..5d3b1d92b8cc0 100644
--- a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
+++ b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
@@ -68,6 +68,10 @@ public function process(ContainerBuilder $container)
                         '/[^a-z0-9]/i',
                     ), function ($matches) { return strtoupper($matches[0]); }, $event['event']);
                     $event['method'] = preg_replace('/[^a-z0-9]/i', '', $event['method']);
+
+                    if (null !== ($class = $container->getDefinition($id)->getClass()) && ($r = $container->getReflectionClass($class, false)) && !$r->hasMethod($event['method']) && $r->hasMethod('__invoke')) {
+                        $event['method'] = '__invoke';
+                    }
                 }
 
                 $definition->addMethodCall('addListener', array($event['event'], array(new ServiceClosureArgument(new Reference($id)), $event['method']), $priority));
diff --git a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
index dbb1aa5c57b57..19e19f83dbf24 100644
--- a/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
+++ b/src/Symfony/Component/EventDispatcher/Tests/DependencyInjection/RegisterListenersPassTest.php
@@ -166,6 +166,47 @@ public function testEventSubscriberUnresolvableClassName()
         $registerListenersPass = new RegisterListenersPass();
         $registerListenersPass->process($container);
     }
+
+    public function testInvokableEventListener()
+    {
+        $container = new ContainerBuilder();
+        $container->register('foo', \stdClass::class)->addTag('kernel.event_listener', array('event' => 'foo.bar'));
+        $container->register('bar', InvokableListenerService::class)->addTag('kernel.event_listener', array('event' => 'foo.bar'));
+        $container->register('baz', InvokableListenerService::class)->addTag('kernel.event_listener', array('event' => 'event'));
+        $container->register('event_dispatcher', \stdClass::class);
+
+        $registerListenersPass = new RegisterListenersPass();
+        $registerListenersPass->process($container);
+
+        $definition = $container->getDefinition('event_dispatcher');
+        $expectedCalls = array(
+            array(
+                'addListener',
+                array(
+                    'foo.bar',
+                    array(new ServiceClosureArgument(new Reference('foo')), 'onFooBar'),
+                    0,
+                ),
+            ),
+            array(
+                'addListener',
+                array(
+                    'foo.bar',
+                    array(new ServiceClosureArgument(new Reference('bar')), '__invoke'),
+                    0,
+                ),
+            ),
+            array(
+                'addListener',
+                array(
+                    'event',
+                    array(new ServiceClosureArgument(new Reference('baz')), 'onEvent'),
+                    0,
+                ),
+            ),
+        );
+        $this->assertEquals($expectedCalls, $definition->getMethodCalls());
+    }
 }
 
 class SubscriberService implements \Symfony\Component\EventDispatcher\EventSubscriberInterface
@@ -177,3 +218,14 @@ public static function getSubscribedEvents()
         );
     }
 }
+
+class InvokableListenerService
+{
+    public function __invoke()
+    {
+    }
+
+    public function onEvent()
+    {
+    }
+}