Update to Drupal 8.0.0 beta 14. For more information, see https://drupal.org/node/2544542

core/lib/Drupal/Core/Http/Client.php

@@ -1,70 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\Http\Client.
- */
-
-namespace Drupal\Core\Http;
-
-use Drupal\Component\Utility\NestedArray;
-use Drupal\Core\Site\Settings;
-use GuzzleHttp\Client as GuzzleClient;
-use GuzzleHttp\Event\SubscriberInterface;
-
-/**
- * Drupal default HTTP client class.
- */
-class Client extends GuzzleClient {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function __construct(array $config = []) {
-    $default_config = array(
-      // Security consideration: we must not use the certificate authority
-      // file shipped with Guzzle because it can easily get outdated if a
-      // certificate authority is hacked. Instead, we rely on the certificate
-      // authority file provided by the operating system which is more likely
-      // going to be updated in a timely fashion. This overrides the default
-      // path to the pem file bundled with Guzzle.
-      'verify' => TRUE,
-      'timeout' => 30,
-      'headers' => array(
-        'User-Agent' => 'Drupal/' . \Drupal::VERSION . ' (+https://www.drupal.org/) ' . static::getDefaultUserAgent(),
-      ),
-    );
-
-    // The entire config array is merged/configurable to allow Guzzle client
-    // options outside of 'defaults' to be changed, such as 'adapter', or
-    // 'message_factory'.
-    $config = NestedArray::mergeDeep(array('defaults' => $default_config), $config, Settings::get('http_client_config', array()));
-
-    parent::__construct($config);
-  }
-
-  /**
-   * Attaches an event subscriber.
-   *
-   * @param \GuzzleHttp\Event\SubscriberInterface $subscriber
-   *   The subscriber to attach.
-   *
-   * @see \GuzzleHttp\Event\Emitter::attach()
-   */
-  public function attach(SubscriberInterface $subscriber) {
-    $this->getEmitter()->attach($subscriber);
-  }
-
-  /**
-   * Detaches an event subscriber.
-   *
-   * @param \GuzzleHttp\Event\SubscriberInterface $subscriber
-   *   The subscriber to detach.
-   *
-   * @see \GuzzleHttp\Event\Emitter::detach()
-   */
-  public function detach(SubscriberInterface $subscriber) {
-    $this->getEmitter()->detach($subscriber);
-  }
-
-}

core/lib/Drupal/Core/Http/ClientFactory.php

@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Http\ClientFactory.
+ */
+
+namespace Drupal\Core\Http;
+
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Site\Settings;
+use GuzzleHttp\Client;
+use GuzzleHttp\HandlerStack;
+
+/**
+ * Helper class to construct a HTTP client with Drupal specific config.
+ */
+class ClientFactory {
+
+  /**
+   * The handler stack.
+   *
+   * @var \GuzzleHttp\HandlerStack
+   */
+  protected $stack;
+
+  /**
+   * Constructs a new ClientFactory instance.
+   *
+   * @param \GuzzleHttp\HandlerStack $stack
+   *   The handler stack.
+   */
+  public function __construct(HandlerStack $stack) {
+    $this->stack = $stack;
+  }
+
+  /**
+   * Constructs a new client object from some configuration.
+   *
+   * @param array $config
+   *   The config for the client.
+   *
+   * @return \GuzzleHttp\Client
+   *   The HTTP client.
+   */
+  public function fromOptions(array $config = []) {
+    $default_config = [
+      // Security consideration: we must not use the certificate authority
+      // file shipped with Guzzle because it can easily get outdated if a
+      // certificate authority is hacked. Instead, we rely on the certificate
+      // authority file provided by the operating system which is more likely
+      // going to be updated in a timely fashion. This overrides the default
+      // path to the pem file bundled with Guzzle.
+      'verify' => TRUE,
+      'timeout' => 30,
+      'headers' => [
+        'User-Agent' => 'Drupal/' . \Drupal::VERSION . ' (+https://www.drupal.org/) ' . \GuzzleHttp\default_user_agent(),
+      ],
+      'handler' => $this->stack,
+    ];
+
+    $config = NestedArray::mergeDeep($default_config, Settings::get('http_client_config', []), $config);
+
+    return new Client($config);
+  }
+
+}

core/lib/Drupal/Core/Http/HandlerStackConfigurator.php

@@ -0,0 +1,94 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Http\HandlerStackConfigurator.
+ */
+
+namespace Drupal\Core\Http;
+
+use GuzzleHttp\HandlerStack;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Defines a class for configuring middlewares on the http handler stack.
+ *
+ * The http_client service requires a handler stack to perform http requests.
+ * This is provided by the http_handler_stack service. Modules wishing to add
+ * additional middlewares to the handler stack can create services and tag them
+ * as http_client_middleware. Each service must contain an __invoke method that
+ * returns a closure which will serve as the middleware.
+ *
+ * @see https://guzzle.readthedocs.org/en/latest/handlers-and-middleware.html
+ *
+ * @see \Drupal\Core\Http\Client
+ * @see \Drupal\Core\Test\HttpClientMiddleware\TestHttpClientMiddleware
+ */
+class HandlerStackConfigurator {
+
+  /**
+   * Array of middlewares to add to the handler stack.
+   *
+   * @var callable[]
+   */
+  protected $middlewares = NULL;
+
+  /**
+   * A list of used middleware service IDs.
+   *
+   * @var string[]
+   */
+  protected $middlewareIds = [];
+
+  /**
+   * The service container.
+   *
+   * @var \Symfony\Component\DependencyInjection\ContainerInterface
+   */
+  protected $container;
+
+  /**
+   * Contructs a new HandlerStackConfigurator object.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
+   *   The service container.
+   * @param string[] $middleware_ids
+   *   The middleware IDs.
+   */
+  public function __construct(ContainerInterface $container, array $middleware_ids) {
+    $this->middlewareIds = $middleware_ids;
+    $this->container = $container;
+  }
+
+  /**
+   * Ensures that the middlewares are initialized.
+   */
+  protected function initializeMiddlewares() {
+    if (!isset($this->middlewares)) {
+      $this->middlewares = [];
+      foreach ($this->middlewareIds as $middleware_id) {
+        $middleware = $this->container->get($middleware_id);
+        if (is_callable($middleware)) {
+          $this->middlewares[$middleware_id] = $middleware();
+        }
+        else {
+          throw new \InvalidArgumentException('Middlewares need to implement __invoke, see https://guzzle.readthedocs.org/en/latest/handlers-and-middleware.html for more information about middlewares.');
+        }
+      }
+    }
+  }
+
+  /**
+   * Configures the stack using services tagged as http_client_middleware.
+   *
+   * @param \GuzzleHttp\HandlerStack $handler_stack
+   *   The handler stack
+   */
+  public function configure(HandlerStack $handler_stack) {
+    $this->initializeMiddlewares();
+    foreach ($this->middlewares as $middleware_id => $middleware) {
+      $handler_stack->push($middleware, $middleware_id);
+    }
+  }
+
+}