[EventDispatcher] A compiler pass for aliased userland events.

Author: derrabus

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.4.0
+-----
+
+* `AddEventAliasesPass` has been added, allowing applications and bundles to extend the event alias mapping used by `RegisterListenersPass`.
+
 4.3.0
 -----
 

DependencyInjection/AddEventAliasesPass.php

@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\EventDispatcher\DependencyInjection;
+
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * This pass allows bundles to extend the list of event aliases.
+ *
+ * @author Alexander M. Turek <[email protected]>
+ */
+class AddEventAliasesPass implements CompilerPassInterface
+{
+    private $eventAliases;
+    private $eventAliasesParameter;
+
+    public function __construct(array $eventAliases, string $eventAliasesParameter = 'event_dispatcher.event_aliases')
+    {
+        $this->eventAliases = $eventAliases;
+        $this->eventAliasesParameter = $eventAliasesParameter;
+    }
+
+    public function process(ContainerBuilder $container): void
+    {
+        $eventAliases = $container->hasParameter($this->eventAliasesParameter) ? $container->getParameter($this->eventAliasesParameter) : [];
+
+        $container->setParameter(
+            $this->eventAliasesParameter,
+            array_merge($eventAliases, $this->eventAliases)
+        );
+    }
+}

Tests/DependencyInjection/RegisterListenersPassTest.php

@@ -15,6 +15,7 @@
 use Symfony\Component\DependencyInjection\Argument\ServiceClosureArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\EventDispatcher\DependencyInjection\AddEventAliasesPass;
 use Symfony\Component\EventDispatcher\DependencyInjection\RegisterListenersPass;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
@@ -67,6 +68,9 @@ public function testAliasedEventSubscriber(): void
         $builder->register('my_event_subscriber', AliasedSubscriber::class)
             ->addTag('kernel.event_subscriber');
 
+        $eventAliasPass = new AddEventAliasesPass([CustomEvent::class => 'custom_event']);
+        $eventAliasPass->process($builder);
+
         $registerListenersPass = new RegisterListenersPass();
         $registerListenersPass->process($builder);
 
@@ -79,6 +83,14 @@ public function testAliasedEventSubscriber(): void
                     0,
                 ],
             ],
+            [
+                'addListener',
+                [
+                    'custom_event',
+                    [new ServiceClosureArgument(new Reference('my_event_subscriber')), 'onCustomEvent'],
+                    0,
+                ],
+            ],
         ];
         $this->assertEquals($expectedCalls, $builder->getDefinition('event_dispatcher')->getMethodCalls());
     }
@@ -202,8 +214,12 @@ public function testAliasedEventListener(): void
         $container = new ContainerBuilder();
         $container->setParameter('event_dispatcher.event_aliases', [AliasedEvent::class => 'aliased_event']);
         $container->register('foo', InvokableListenerService::class)->addTag('kernel.event_listener', ['event' => AliasedEvent::class, 'method' => 'onEvent']);
+        $container->register('bar', InvokableListenerService::class)->addTag('kernel.event_listener', ['event' => CustomEvent::class, 'method' => 'onEvent']);
         $container->register('event_dispatcher');
 
+        $eventAliasPass = new AddEventAliasesPass([CustomEvent::class => 'custom_event']);
+        $eventAliasPass->process($container);
+
         $registerListenersPass = new RegisterListenersPass();
         $registerListenersPass->process($container);
 
@@ -217,6 +233,14 @@ public function testAliasedEventListener(): void
                     0,
                 ],
             ],
+            [
+                'addListener',
+                [
+                    'custom_event',
+                    [new ServiceClosureArgument(new Reference('bar')), 'onEvent'],
+                    0,
+                ],
+            ],
         ];
         $this->assertEquals($expectedCalls, $definition->getMethodCalls());
     }
@@ -249,10 +273,15 @@ public static function getSubscribedEvents(): array
     {
         return [
             AliasedEvent::class => 'onAliasedEvent',
+            CustomEvent::class => 'onCustomEvent',
         ];
     }
 }
 
 final class AliasedEvent
 {
 }
+
+final class CustomEvent
+{
+}