symfony · nicolas-grekas · Jun 4, 2018 · Apr 27, 2018
diff --git a/src/Symfony/Component/DependencyInjection/CHANGELOG.md b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.2.0
+-----
+
+ * added `ServiceSubscriberTrait`
+
 4.1.0
 -----
 

diff --git a/src/Symfony/Component/DependencyInjection/ServiceSubscriberTrait.php b/src/Symfony/Component/DependencyInjection/ServiceSubscriberTrait.php
@@ -0,0 +1,61 @@
+<?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\Component\DependencyInjection;
+
+use Psr\Container\ContainerInterface;
+
+/**
+ * Implementation of ServiceSubscriberInterface that determines subscribed services from
+ * private method return types. Service ids are available as "ClassName::methodName".
+ *
+ * @author Kevin Bond <kevinbond@gmail.com>
+ */
+trait ServiceSubscriberTrait
+{
+    /** @var ContainerInterface */
+    private $container;
+
+    public static function getSubscribedServices(): array
+    {
+        static $services;
+
+        if (null !== $services) {
+            return $services;
+        }
+
+        $services = \is_callable(array('parent', __FUNCTION__)) ? parent::getSubscribedServices() : array();
+
+        foreach ((new \ReflectionClass(self::class))->getMethods() as $method) {
+            if ($method->isStatic() || $method->isAbstract() || $method->isGenerator() || $method->isInternal() || $method->getNumberOfRequiredParameters()) {
+                continue;
+            }
+
+            if (self::class === $method->getDeclaringClass()->name && ($returnType = $method->getReturnType()) && !$returnType->isBuiltin()) {
+                $services[self::class.'::'.$method->name] = '?'.$returnType->getName();
+            }
+        }
+
+        return $services;
+    }
+
+    /**
+     * @required
+     */
+    public function setContainer(ContainerInterface $container)
+    {
+        $this->container = $container;
+
+        if (\is_callable(array('parent', __FUNCTION__))) {
+            return parent::setContainer($container);
+        }
+    }
+}
diff --git a/...mfony/Component/DependencyInjection/Tests/Compiler/RegisterServiceSubscribersPassTest.php b/...mfony/Component/DependencyInjection/Tests/Compiler/RegisterServiceSubscribersPassTest.php
@@ -21,7 +21,12 @@
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\ServiceLocator;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\CustomDefinition;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestDefinition1;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestDefinition2;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestDefinition3;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriber;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriberChild;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\TestServiceSubscriberParent;
 use Symfony\Component\DependencyInjection\TypedReference;
 
 require_once __DIR__.'/../Fixtures/includes/classes.php';
@@ -136,4 +141,29 @@ public function testExtraServiceSubscriber()
         $container->register(TestServiceSubscriber::class, TestServiceSubscriber::class);
         $container->compile();
     }
+
+    public function testServiceSubscriberTrait()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('foo', TestServiceSubscriberChild::class)
+            ->addMethodCall('setContainer', array(new Reference(PsrContainerInterface::class)))
+            ->addTag('container.service_subscriber')
+        ;
+
+        (new RegisterServiceSubscribersPass())->process($container);
+        (new ResolveServiceSubscribersPass())->process($container);
+
+        $foo = $container->getDefinition('foo');
+        $locator = $container->getDefinition((string) $foo->getMethodCalls()[0][1][0]);
+
+        $expected = array(
+            TestServiceSubscriberChild::class.'::invalidDefinition' => new ServiceClosureArgument(new TypedReference('Symfony\Component\DependencyInjection\Tests\Fixtures\InvalidDefinition', 'Symfony\Component\DependencyInjection\Tests\Fixtures\InvalidDefinition', ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
+            TestServiceSubscriberChild::class.'::testDefinition2' => new ServiceClosureArgument(new TypedReference(TestDefinition2::class, TestDefinition2::class, ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
+            TestServiceSubscriberChild::class.'::testDefinition3' => new ServiceClosureArgument(new TypedReference(TestDefinition3::class, TestDefinition3::class, ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
+            TestServiceSubscriberParent::class.'::testDefinition1' => new ServiceClosureArgument(new TypedReference(TestDefinition1::class, TestDefinition1::class, ContainerInterface::IGNORE_ON_INVALID_REFERENCE)),
+        );
+
+        $this->assertEquals($expected, $container->getDefinition((string) $locator->getFactory()[0])->getArgument(0));
+    }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition1.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition1.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+use Symfony\Component\DependencyInjection\Definition;
+
+class TestDefinition1 extends Definition
+{
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition2.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition2.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+use Symfony\Component\DependencyInjection\Definition;
+
+class TestDefinition2 extends Definition
+{
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition3.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestDefinition3.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+use Symfony\Component\DependencyInjection\Definition;
+
+class TestDefinition3 extends Definition
+{
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberChild.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberChild.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+use Symfony\Component\DependencyInjection\ServiceSubscriberTrait;
+
+class TestServiceSubscriberChild extends TestServiceSubscriberParent
+{
+    use ServiceSubscriberTrait, TestServiceSubscriberTrait;
+
+    private function testDefinition2(): TestDefinition2
+    {
+        return $this->container->get(__METHOD__);
+    }
+
+    private function invalidDefinition(): InvalidDefinition
+    {
+        return $this->container->get(__METHOD__);
+    }
+
+    private function privateFunction1(): string
+    {
+    }
+
+    private function privateFunction2(): string
+    {
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberParent.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberParent.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
+use Symfony\Component\DependencyInjection\ServiceSubscriberTrait;
+
+class TestServiceSubscriberParent implements ServiceSubscriberInterface
+{
+    use ServiceSubscriberTrait;
+
+    private function testDefinition1(): TestDefinition1
+    {
+        return $this->container->get(__METHOD__);
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberTrait.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/TestServiceSubscriberTrait.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+trait TestServiceSubscriberTrait
+{
+    private function testDefinition3(): TestDefinition3
+    {
+        return $this->container->get(__CLASS__.'::'.__FUNCTION__);
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/ServiceSubscriberTraitTest.php b/src/Symfony/Component/DependencyInjection/Tests/ServiceSubscriberTraitTest.php
@@ -0,0 +1,63 @@
+<?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\Component\DependencyInjection\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Psr\Container\ContainerInterface;
+use Symfony\Component\DependencyInjection\Container;
+use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
+use Symfony\Component\DependencyInjection\ServiceSubscriberTrait;
+
+class ServiceSubscriberTraitTest extends TestCase
+{
+    public function testMethodsOnParentsAndChildrenAreIgnoredInGetSubscribedServices()
+    {
+        $expected = array(TestService::class.'::aService' => '?Symfony\Component\DependencyInjection\Tests\Service2');
+
+        $this->assertEquals($expected, ChildTestService::getSubscribedServices());
+    }
+
+    public function testSetContainerIsCalledOnParent()
+    {
+        $container = new Container();
+
+        $this->assertSame($container, (new TestService())->setContainer($container));
+    }
+}
+
+class ParentTestService
+{
+    public function aParentService(): Service1
+    {
+    }
+
+    public function setContainer(ContainerInterface $container)
+    {
+        return $container;
+    }
+}
+
+class TestService extends ParentTestService implements ServiceSubscriberInterface
+{
+    use ServiceSubscriberTrait;
+
+    public function aService(): Service2
+    {
+    }
+}
+
+class ChildTestService extends TestService
+{
+    public function aChildService(): Service3
+    {
+    }
+}