Implementation of kernel.event_subscriber tag for services.

src/Symfony/Bundle/FrameworkBundle/ContainerAwareEventDispatcher.php

@@ -21,6 +21,7 @@
  *
  * @author Fabien Potencier <fabien@symfony.com>
  * @author Bernhard Schussek <bernhard.schussek@symfony.com>
+ * @author Jordan Alliot <jordan.alliot@gmail.com>
  */
 class ContainerAwareEventDispatcher extends EventDispatcher
 {
@@ -103,6 +104,32 @@ public function getListeners($eventName = null)
         return parent::getListeners($eventName);
     }
 
+    /**
+     * Adds a service as event subscriber
+     *
+     * If this service is created by a factory, its class value must be correctly filled.
+     * The service's class must implement Symfony\Component\EventDispatcher\EventSubscriberInterface.
+     *
+     * @param string $serviceId The service ID of the subscriber service
+     * @param string $class     The service's class name
+     */
+    public function addSubscriberService($serviceId, $class)
+    {
+        $refClass = new \ReflectionClass($class);
+        $interface = 'Symfony\Component\EventDispatcher\EventSubscriberInterface';
+        if (!$refClass->implementsInterface($interface)) {
+            throw new \InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $serviceId, $interface));
+        }
+
+        foreach ($class::getSubscribedEvents() as $eventName => $params) {
+            if (is_string($params)) {
+                $this->listenerIds[$eventName][] = array($serviceId, $params, 0);
+            } else {
+                $this->listenerIds[$eventName][] = array($serviceId, $params[0], $params[1]);
+            }
+        }
+    }
+
     /**
      * {@inheritDoc}
      *

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/RegisterKernelListenersPass.php

@@ -43,5 +43,18 @@ public function process(ContainerBuilder $container)
                 $definition->addMethodCall('addListenerService', array($event['event'], array($id, $event['method']), $priority));
             }
         }
+
+        foreach ($container->findTaggedServiceIds('kernel.event_subscriber') as $id => $attributes) {
+            // We must assume that the class value has been correcly filled, even if the service is created by a factory
+            $class = $container->getDefinition($id)->getClass();
+
+            $refClass = new \ReflectionClass($class);
+            $interface = 'Symfony\Component\EventDispatcher\EventSubscriberInterface';
+            if (!$refClass->implementsInterface($interface)) {
+                throw new \InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, $interface));
+            }
+
+            $definition->addMethodCall('addSubscriberService', array($id, $class));
+        }
     }
 }

src/Symfony/Bundle/FrameworkBundle/Tests/ContainerAwareEventDispatcherTest.php

@@ -14,6 +14,7 @@
 use Symfony\Component\DependencyInjection\Container;
 use Symfony\Bundle\FrameworkBundle\ContainerAwareEventDispatcher;
 use Symfony\Component\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\DependencyInjection\Scope;
 
 class ContainerAwareEventDispatcherTest extends \PHPUnit_Framework_TestCase
@@ -39,6 +40,36 @@ public function testAddAListenerService()
         $dispatcher->dispatch('onEvent', $event);
     }
 
+    public function testAddASubscriberService()
+    {
+        $event = new Event();
+
+        $service = $this->getMock('Symfony\Bundle\FrameworkBundle\Tests\SubscriberService');
+
+        $service
+            ->expects($this->once())
+            ->method('onEvent')
+            ->with($event)
+        ;
+
+        $container = new Container();
+        $container->set('service.subscriber', $service);
+
+        $dispatcher = new ContainerAwareEventDispatcher($container);
+        $dispatcher->addSubscriberService('service.subscriber', 'Symfony\Bundle\FrameworkBundle\Tests\SubscriberService');
+
+        $dispatcher->dispatch('onEvent', $event);
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testTriggerASubscriberDoesntImplementInterface()
+    {
+        $dispatcher = new ContainerAwareEventDispatcher(new Container());
+        $dispatcher->addSubscriberService('service.subscriber', 'Symfony\Bundle\FrameworkBundle\Tests\Service');
+    }
+
     public function testPreventDuplicateListenerService()
     {
         $event = new Event();
@@ -174,3 +205,16 @@ function onEvent(Event $e)
     {
     }
 }
+
+class SubscriberService implements EventSubscriberInterface
+{
+    static function getSubscribedEvents() {
+        return array(
+            'onEvent' => 'onEvent',
+        );
+    }
+
+    function onEvent(Event $e)
+    {
+    }
+}

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/RegisterKernelListenersPassTest.php

@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\FrameworkBundle\Tests\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\RegisterKernelListenersPass;
+
+class RegisterKernelListenersPassTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Tests that event subscribers not implementing EventSubscriberInterface
+     * trigger an exception.
+     *
+     * @expectedException \InvalidArgumentException
+     */
+    public function testEventSubscriberWithoutInterface()
+    {
+        // one service, not implementing any interface
+        $services = array(
+            'my_event_subscriber' => array(0 => array()),
+        );
+
+        $definition = $this->getMock('Symfony\Component\DependencyInjection\Definition');
+        $definition->expects($this->atLeastOnce())
+            ->method('getClass')
+            ->will($this->returnValue('stdClass'));
+
+        $builder = $this->getMock('Symfony\Component\DependencyInjection\ContainerBuilder');
+        $builder->expects($this->any())
+            ->method('hasDefinition')
+            ->will($this->returnValue(true));
+
+        // We don't test kernel.event_listener here
+        $builder->expects($this->atLeastOnce())
+            ->method('findTaggedServiceIds')
+            ->will($this->onConsecutiveCalls(array(), $services));
+
+        $builder->expects($this->atLeastOnce())
+            ->method('getDefinition')
+            ->will($this->returnValue($definition));
+
+        $registerListenersPass = new RegisterKernelListenersPass();
+        $registerListenersPass->process($builder);
+    }
+
+    public function testValidEventSubscriber()
+    {
+        $services = array(
+            'my_event_subscriber' => array(0 => array()),
+        );
+
+        $definition = $this->getMock('Symfony\Component\DependencyInjection\Definition');
+        $definition->expects($this->atLeastOnce())
+            ->method('getClass')
+            ->will($this->returnValue('Symfony\Bundle\FrameworkBundle\Tests\DependencyInjection\Compiler\SubscriberService'));
+
+        $builder = $this->getMock('Symfony\Component\DependencyInjection\ContainerBuilder');
+        $builder->expects($this->any())
+            ->method('hasDefinition')
+            ->will($this->returnValue(true));
+
+        // We don't test kernel.event_listener here
+        $builder->expects($this->atLeastOnce())
+            ->method('findTaggedServiceIds')
+            ->will($this->onConsecutiveCalls(array(), $services));
+
+        $builder->expects($this->atLeastOnce())
+            ->method('getDefinition')
+            ->will($this->returnValue($definition));
+
+        $registerListenersPass = new RegisterKernelListenersPass();
+        $registerListenersPass->process($builder);
+    }
+}
+
+class SubscriberService implements \Symfony\Component\EventDispatcher\EventSubscriberInterface
+{
+    static function getSubscribedEvents() {}
+}