Add listener for gathering services (#215)

Author: cspray

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased Changes
+
+## [v1.5.2](https://github.com/cspray/annoated-container/tree/v1.5.2) - 2022-08-13
+
+### Added
+
+- Added a `ServiceGatherListener` that encapsulates gathering a collection of services from the Container matching a given type. One of the primary use cases is to prepare a service that needs a collection of other services. For example, adding Controllers to a HTTP Routing system.
+
 ## [v1.5.1](https://github.com/cspray/annotated-container/tree/v1.5.1) - 2022-08-13
 
 ### Fixed

VERSION

@@ -1 +1 @@
-1.5.1
+1.5.2

src/ServiceGatheringListener.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Cspray\AnnotatedContainer;
+
+use Cspray\Typiphy\ObjectType;
+
+abstract class ServiceGatheringListener implements AnnotatedContainerListener {
+
+    private ContainerDefinition $containerDefinition;
+    private AnnotatedContainer $container;
+
+    final public function handle(AnnotatedContainerEvent $event) : void {
+        if ($event->getLifecycle() === AnnotatedContainerLifecycle::BeforeContainerCreation) {
+            $containerDefinition = $event->getTarget();
+            assert($containerDefinition instanceof ContainerDefinition);
+            $this->containerDefinition = $containerDefinition;
+        } else if ($event->getLifecycle() === AnnotatedContainerLifecycle::AfterContainerCreation) {
+            $container = $event->getTarget();
+            assert($container instanceof AnnotatedContainer);
+            $this->container = $container;
+            $this->doServiceGathering();
+        }
+    }
+
+    final protected function getServicesOfType(ObjectType $objectType) : \Generator {
+        foreach ($this->containerDefinition->getServiceDefinitions() as $serviceDefinition) {
+            if ($serviceDefinition->isAbstract()) {
+                continue;
+            }
+
+            /** @var class-string $objectName */
+            $objectName = $objectType->getName();
+            if (is_a($serviceDefinition->getType()->getName(), $objectName, true)) {
+                yield $this->container->get($serviceDefinition->getType()->getName());
+            }
+        }
+    }
+
+    abstract protected function doServiceGathering() : void;
+
+}

test/Helper/StubServiceGatheringListener.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Cspray\AnnotatedContainer\Helper;
+
+use Cspray\AnnotatedContainer\ServiceGatheringListener;
+use Cspray\Typiphy\ObjectType;
+
+final class StubServiceGatheringListener extends ServiceGatheringListener {
+
+    private array $services = [];
+
+    public function __construct(
+        private readonly ObjectType $serviceType
+    ) {}
+
+    protected function doServiceGathering() : void {
+        foreach ($this->getServicesOfType($this->serviceType) as $service) {
+            $this->services[] = $service;
+        }
+    }
+
+    public function getServices() : array {
+        return $this->services;
+    }
+}

test/ServiceGatheringListenerTest.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Cspray\AnnotatedContainer;
+
+use Cspray\AnnotatedContainer\Helper\StubServiceGatheringListener;
+use Cspray\AnnotatedContainerFixture\Fixtures;
+use PHPUnit\Framework\TestCase;
+
+final class ServiceGatheringListenerTest extends TestCase {
+
+    public function testNoServicesReturnsEmptyArray() : void {
+        $subject = new StubServiceGatheringListener(Fixtures::implicitAliasedServices()->fooInterface());
+        eventEmitter()->registerListener($subject);
+        $containerDefinition = compiler()->compile(
+            ContainerDefinitionCompileOptionsBuilder::scanDirectories(Fixtures::singleConcreteService()->getPath())->build()
+        );
+        containerFactory()->createContainer($containerDefinition);
+
+        self::assertSame([] , $subject->getServices());
+    }
+
+    public function testSingleConcreteServiceReturnsOneItemArray() : void {
+        $subject = new StubServiceGatheringListener(Fixtures::implicitAliasedServices()->fooInterface());
+        eventEmitter()->registerListener($subject);
+        $containerDefinition = compiler()->compile(
+            ContainerDefinitionCompileOptionsBuilder::scanDirectories(Fixtures::implicitAliasedServices()->getPath())->build()
+        );
+        $container = containerFactory()->createContainer($containerDefinition);
+
+        self::assertSame([$container->get(Fixtures::implicitAliasedServices()->fooImplementation()->getName())], $subject->getServices());
+    }
+
+    public function testMultipleConcreteServices() : void {
+        $subject = new StubServiceGatheringListener(Fixtures::ambiguousAliasedServices()->fooInterface());
+        eventEmitter()->registerListener($subject);
+        $containerDefinition = compiler()->compile(
+            ContainerDefinitionCompileOptionsBuilder::scanDirectories(Fixtures::ambiguousAliasedServices()->getPath())->build()
+        );
+        $container = containerFactory()->createContainer($containerDefinition);
+
+        $services = $subject->getServices();
+        usort($services, fn($a, $b) => $a::class <=> $b::class);
+
+        self::assertSame([
+            $container->get(Fixtures::ambiguousAliasedServices()->barImplementation()->getName()),
+            $container->get(Fixtures::ambiguousAliasedServices()->bazImplementation()->getName()),
+            $container->get(Fixtures::ambiguousAliasedServices()->quxImplementation()->getName())
+        ], $services);
+    }
+
+}