README.md

@@ -0,0 +1,4 @@
+# Autowire Example
+
+An example module to demonstrate autowiring service classes in Drupal 8, as
+well as how to define Controllers as Services.

autowire_example.info.yml

@@ -1,3 +1,5 @@
-name: Foo
+name: 'Autowire Example'
 type: module
+description: 'An example module to demonstrate autowiring in Drupal 8.'
 core: 8.x
+package: 'Example modules'

autowire_example.module

@@ -1,9 +0,0 @@
-<?php
-
-/**
- * Implements hook_preprocess_HOOK().
- */
-function autowire_example_preprocess_html() {
-  $service = \Drupal::service('autowire_example.test');
-  $service->__invoke();
-}

autowire_example.routing.yml

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+autowire_example.user_count:
+  path: '/user-count'
+  defaults:
+    _controller: 'Drupal\autowire_example\Controller\ExampleController::__invoke'
+  requirements:
+    _access: 'TRUE'

autowire_example.services.yml

@@ -1,5 +1,9 @@
 services:
-  autowire_example.test:
+  Drupal\Core\Entity\EntityTypeManagerInterface:
-    class: Drupal\autowire_example\Service\ExampleService
+    alias: entity_type.manager
-    arguments:
+
-      - '@current_user'
+  Drupal\autowire_example\Controller\ExampleController:
+    autowire: true
+
+  Drupal\autowire_example\Service\UserCounter:
+    autowire: true

src/Controller/ExampleController.php

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+<?php
+
+namespace Drupal\autowire_example\Controller;
+
+use Drupal\autowire_example\Service\UserCounter;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * An example controller.
+ */
+class ExampleController {
+
+  use StringTranslationTrait;
+
+  /**
+   * The user counter service.
+   *
+   * @var \Drupal\autowire_example\Service\UserCounter
+   */
+  private $userCounter;
+
+  /**
+   * ExampleController constructor.
+   *
+   * @param \Drupal\autowire_example\Service\UserCounter $user_counter
+   *   The user counter service.
+   */
+  public function __construct(UserCounter $user_counter) {
+    $this->userCounter = $user_counter;
+  }
+
+  /**
+   * Display the username of the current user.
+   *
+   * @return array
+   *   A render array.
+   */
+  public function __invoke() {
+    return [
+      '#markup' => $this->formatPlural(
+        number_format($this->userCounter->getActiveUserCount()),
+        'This site has 1 active user.',
+        'This site has @count active users.'
+      )
+    ];
+  }
+  
+}

src/Service/ExampleService.php

@@ -1,29 +0,0 @@
-<?php
-
-namespace Drupal\autowire_example\Service;
-
-use Drupal\Core\Session\AccountProxyInterface;
-
-class ExampleService {
-
-  /**
-   * @var \Drupal\Core\Session\AccountProxyInterface
-   */
-  private $currentUser;
-
-  /**
-   * Bar constructor.
-   *
-   * @param \Drupal\Core\Session\AccountProxyInterface $current_user
-   *   The current user.
-   */
-  public function __construct(AccountProxyInterface $current_user) {
-    $this->currentUser = $current_user;
-  }
-
-  public function __invoke() {
-    dump($this->currentUser->id());
-    die;
-  }
-
-}

src/Service/UserCounter.php

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+<?php
+
+namespace Drupal\autowire_example\Service;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+
+/**
+ * A service to count users.
+ */
+class UserCounter {
+
+  /**
+   * The user storage instance.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  private $userStorage;
+
+  /**
+   * UserCounter constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   */
+  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
+    $this->userStorage = $entity_type_manager->getStorage('user');
+  }
+
+  /**
+   * Count the active users.
+   *
+   * @return integer
+   *   The number of active users.
+   */
+  public function getActiveUserCount() {
+    return (int) $this->userStorage
+      ->getQuery()
+      ->condition('status', 1)
+      ->count()
+      ->execute();
+  }
+
+}

tests/src/Kernel/Service/UserCounterTest.php

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+<?php
+
+namespace Drupal\Tests\autowire_example\Kernel\Service;
+
+use Drupal\autowire_example\Service\UserCounter;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
+
+/**
+ * Test the user counter service.
+ */
+class UserCounterTest extends EntityKernelTestBase {
+
+  /**
+   * The user counter service.
+   *
+   * @var \Drupal\autowire_example\Service\UserCounter
+   */
+  private $userCounter;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['autowire_example'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->userCounter = $this->container->get(UserCounter::class);
+  }
+
+  /** @test */
+  public function active_users_are_counted() {
+    $this->createUser(['status' => 1]);
+    $this->createUser(['status' => 1]);
+
+    $this->assertEquals(2, $this->userCounter->getActiveUserCount());
+  }
+
+  /** @test */
+  public function blocked_users_are_not_counted() {
+    $this->createUser(['status' => 1]);
+    $this->createUser(['status' => 0]);
+
+    $this->assertEquals(1, $this->userCounter->getActiveUserCount());
+  }
+
+}