[DI] add docs for SubscribedService::$attributes

Author: kbond

service_container/service_subscribers_locators.rst

@@ -243,6 +243,55 @@ service type to a service.
     The ``key`` attribute can be omitted if the service name internally is the
     same as in the service container.
 
+Add Dependency Injection Attributes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. versionadded:: 6.2
+
+    The ability to add attributes was introduced in Symfony 6.2.
+
+As an alternate to aliasing services in your configuration, you can also configure
+the following dependency injection attributes in the ``getSubscribedServices()``
+method directly:
+
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\Autowire`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\TaggedIterator`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\TaggedLocator`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\Target`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\MapDecorated`
+
+This is done by having ``getSubscribedServices()`` return an array of
+:class:`Symfony\\Contracts\\Service\\Attribute\\SubscribedService` objects
+(these can be combined with standard ``string[]`` values)::
+
+    use Psr\Container\ContainerInterface;
+    use Psr\Log\LoggerInterface;
+    use Symfony\Component\DependencyInjection\Attribute\Autowire;
+    use Symfony\Component\DependencyInjection\Attribute\TaggedIterator;
+    use Symfony\Component\DependencyInjection\Attribute\TaggedLocator;
+    use Symfony\Component\DependencyInjection\Attribute\Target;
+    use Symfony\Contracts\Service\Attribute\SubscribedService;
+
+    public static function getSubscribedServices(): array
+    {
+        return [
+            // ...
+            new SubscribedService('logger', LoggerInterface::class, attributes: new Autowire(service: 'monolog.logger.event')),
+
+            // can event use parameters
+            new SubscribedService('env', string, attributes: new Autowire('%kernel.environment%')),
+
+            // Target
+            new SubscribedService('event.logger', LoggerInterface::class, attributes: new Target('eventLogger')),
+
+            // TaggedIterator
+            new SubscribedService('loggers', 'iterable', attributes: new TaggedIterator('logger.tag')),
+
+            // TaggedLocator
+            new SubscribedService('handlers', ContainerInterface::class, attributes: new TaggedLocator('handler.tag')),
+        ];
+    }
+
 Defining a Service Locator
 --------------------------
 
@@ -256,7 +305,7 @@ argument of type ``service_locator``:
         # config/services.yaml
         services:
             App\CommandBus:
-                arguments: 
+                arguments:
                   - !service_locator
                       App\FooCommand: '@app.command_handler.foo'
                       App\BarCommand: '@app.command_handler.bar'
@@ -721,4 +770,63 @@ and compose your services with them::
     as this will include the trait name, not the class name. Instead, use
     ``__CLASS__.'::'.__FUNCTION__`` as the service id.
 
+SubscribedService Attributes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. versionadded:: 6.2
+
+    The ability to add attributes was introduced in Symfony 6.2.
+
+You can use the ``attributes`` argument of ``SubscribedService`` to add any
+of the following dependency injection attributes:
+
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\Autowire`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\TaggedIterator`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\TaggedLocator`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\Target`
+* :class:`Symfony\\Component\\DependencyInjection\\Attribute\\MapDecorated`
+
+Here's an example::
+
+    // src/Service/MyService.php
+    namespace App\Service;
+
+    use Psr\Log\LoggerInterface;
+    use Symfony\Component\DependencyInjection\Attribute\Autowire;
+    use Symfony\Component\DependencyInjection\Attribute\Target;
+    use Symfony\Component\Routing\RouterInterface;
+    use Symfony\Contracts\Service\Attribute\SubscribedService;
+    use Symfony\Contracts\Service\ServiceSubscriberInterface;
+    use Symfony\Contracts\Service\ServiceSubscriberTrait;
+
+    class MyService implements ServiceSubscriberInterface
+    {
+        use ServiceSubscriberTrait;
+
+        public function doSomething()
+        {
+            // $this->environment() ...
+            // $this->router() ...
+            // $this->logger() ...
+        }
+
+        #[SubscribedService(attributes: new Autowire('%kernel.environment%'))]
+        private function environment(): string
+        {
+            return $this->container->get(__METHOD__);
+        }
+
+        #[SubscribedService(attributes: new Autowire(service: 'router'))]
+        private function router(): RouterInterface
+        {
+            return $this->container->get(__METHOD__);
+        }
+
+        #[SubscribedService(attributes: new Target('requestLogger'))]
+        private function logger(): LoggerInterface
+        {
+            return $this->container->get(__METHOD__);
+        }
+    }
+
 .. _`Command pattern`: https://en.wikipedia.org/wiki/Command_pattern