class Client

1. 8.x drupal/core/vendor/guzzle/http/Guzzle/Http/Client.php \Guzzle\Http\Client
2. 8.x drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Client.php \Symfony\Component\HttpKernel\Client

OpmlFeedAdd.php in drupal/core/modules/aggregator/lib/Drupal/aggregator/Form/OpmlFeedAdd.php

Contains \Drupal\aggregator\Form\OpmlFeedAdd.

core.services.yml in drupal/core/core.services.yml

drupal/core/core.services.yml

http_default_client in drupal/core/core.services.yml

Guzzle\Http\Client

class Client extends AbstractHasDispatcher implements ClientInterface {
  const REQUEST_PARAMS = 'request.params';
  const CURL_OPTIONS = 'curl.options';
  const SSL_CERT_AUTHORITY = 'ssl.certificate_authority';
  const DISABLE_REDIRECTS = RedirectPlugin::DISABLE;

  /**
   * @var Collection Default HTTP headers to set on each request
   */
  protected $defaultHeaders;

  /**
   * @var string The user agent string to set on each request
   */
  protected $userAgent;

  /**
   * @var Collection Parameter object holding configuration data
   */
  private $config;

  /**
   * @var Url Base URL of the client
   */
  private $baseUrl;

  /**
   * @var CurlMultiInterface CurlMulti object used internally
   */
  private $curlMulti;

  /**
   * @var UriTemplateInterface URI template owned by the client
   */
  private $uriTemplate;

  /**
   * @var RequestFactoryInterface Request factory used by the client
   */
  protected $requestFactory;

  /**
   * {@inheritdoc}
   */
  public static function getAllEvents() {
    return array(
      self::CREATE_REQUEST,
    );
  }

  /**
   * Client constructor
   *
   * @param string           $baseUrl Base URL of the web service
   * @param array|Collection $config  Configuration settings
   */
  public function __construct($baseUrl = '', $config = null) {
    $this
      ->setConfig($config ?: new Collection());

    // Allow ssl.certificate_authority config setting to control the certificate authority used by curl
    $authority = $this->config
      ->get(self::SSL_CERT_AUTHORITY);

    // Use the system's cacert if in a phar (curl can't read from a phar stream wrapper)
    if (strpos(__FILE__, 'phar://') !== false && (null === $authority || $authority === true)) {
      $authority = 'system';
    }

    // Set the config setting to system to use the certificate authority bundle on your system
    if ($authority !== 'system') {
      $this
        ->setSslVerification($authority !== null ? $authority : true);
    }
    $this
      ->setBaseUrl($baseUrl);
    $this->defaultHeaders = new Collection();
    $this
      ->setRequestFactory(RequestFactory::getInstance());

    // Redirect by default, but allow for redirects to be globally disabled on a client
    if (!$this->config
      ->get(self::DISABLE_REDIRECTS)) {
      $this
        ->addSubscriber(new RedirectPlugin());
    }
  }

  /**
   * {@inheritdoc}
   */
  public final function setConfig($config) {

    // Set the configuration object
    if ($config instanceof Collection) {
      $this->config = $config;
    }
    elseif (is_array($config)) {
      $this->config = new Collection($config);
    }
    else {
      throw new InvalidArgumentException('Config must be an array or Collection');
    }
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public final function getConfig($key = false) {
    return $key ? $this->config
      ->get($key) : $this->config;
  }

  /**
   * {@inheritdoc}
   */
  public final function setSslVerification($certificateAuthority = true, $verifyPeer = true, $verifyHost = 2) {
    $opts = $this->config
      ->get(self::CURL_OPTIONS) ?: array();
    if ($certificateAuthority === true) {

      // use bundled CA bundle, set secure defaults
      $opts[CURLOPT_CAINFO] = __DIR__ . '/Resources/cacert.pem';
      $opts[CURLOPT_SSL_VERIFYPEER] = true;
      $opts[CURLOPT_SSL_VERIFYHOST] = 2;
    }
    elseif ($certificateAuthority === false) {
      unset($opts[CURLOPT_CAINFO]);
      $opts[CURLOPT_SSL_VERIFYPEER] = false;
      $opts[CURLOPT_SSL_VERIFYHOST] = 2;
    }
    elseif ($verifyPeer !== true && $verifyPeer !== false && $verifyPeer !== 1 && $verifyPeer !== 0) {
      throw new InvalidArgumentException('verifyPeer must be 1, 0 or boolean');
    }
    elseif ($verifyHost !== 0 && $verifyHost !== 1 && $verifyHost !== 2) {
      throw new InvalidArgumentException('verifyHost must be 0, 1 or 2');
    }
    else {
      $opts[CURLOPT_SSL_VERIFYPEER] = $verifyPeer;
      $opts[CURLOPT_SSL_VERIFYHOST] = $verifyHost;
      if (is_file($certificateAuthority)) {
        unset($opts[CURLOPT_CAPATH]);
        $opts[CURLOPT_CAINFO] = $certificateAuthority;
      }
      elseif (is_dir($certificateAuthority)) {
        unset($opts[CURLOPT_CAINFO]);
        $opts[CURLOPT_CAPATH] = $certificateAuthority;
      }
    }
    $this->config
      ->set(self::CURL_OPTIONS, $opts);
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function getDefaultHeaders() {
    return $this->defaultHeaders;
  }

  /**
   * {@inheritdoc}
   */
  public function setDefaultHeaders($headers) {
    if ($headers instanceof Collection) {
      $this->defaultHeaders = $headers;
    }
    elseif (is_array($headers)) {
      $this->defaultHeaders = new Collection($headers);
    }
    else {
      throw new InvalidArgumentException('Headers must be an array or Collection');
    }
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function expandTemplate($template, array $variables = null) {
    $expansionVars = $this
      ->getConfig()
      ->getAll();
    if ($variables) {
      $expansionVars = array_merge($expansionVars, $variables);
    }
    return $this
      ->getUriTemplate()
      ->expand($template, $expansionVars);
  }

  /**
   * {@inheritdoc}
   */
  public function setUriTemplate(UriTemplateInterface $uriTemplate) {
    $this->uriTemplate = $uriTemplate;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function getUriTemplate() {
    if (!$this->uriTemplate) {
      $this->uriTemplate = ParserRegistry::getInstance()
        ->getParser('uri_template');
    }
    return $this->uriTemplate;
  }

  /**
   * {@inheritdoc}
   */
  public function createRequest($method = RequestInterface::GET, $uri = null, $headers = null, $body = null) {
    if (!is_array($uri)) {
      $templateVars = null;
    }
    else {
      if (count($uri) != 2 || !isset($uri[1]) || !is_array($uri[1])) {
        throw new InvalidArgumentException('You must provide a URI template followed by an array of template variables ' . 'when using an array for a URI template');
      }
      list($uri, $templateVars) = $uri;
    }
    if (!$uri) {
      $url = $this
        ->getBaseUrl();
    }
    elseif (substr($uri, 0, 4) === 'http') {

      // Use absolute URLs as-is
      $url = $this
        ->expandTemplate($uri, $templateVars);
    }
    else {
      $url = Url::factory($this
        ->getBaseUrl())
        ->combine($this
        ->expandTemplate($uri, $templateVars));
    }
    if ($this->userAgent) {
      $this->defaultHeaders
        ->set('User-Agent', $this->userAgent);
    }

    // If default headers are provided, then merge them into existing headers
    // If a collision occurs, the header is completely replaced
    if (count($this->defaultHeaders)) {
      if ($headers instanceof Collection) {
        $headers = array_merge($this->defaultHeaders
          ->getAll(), $headers
          ->getAll());
      }
      elseif (is_array($headers)) {
        $headers = array_merge($this->defaultHeaders
          ->getAll(), $headers);
      }
      else {
        $headers = $this->defaultHeaders;
      }
    }
    return $this
      ->prepareRequest($this->requestFactory
      ->create($method, (string) $url, $headers, $body));
  }

  /**
   * {@inheritdoc}
   */
  public function getBaseUrl($expand = true) {
    return $expand ? $this
      ->expandTemplate($this->baseUrl) : $this->baseUrl;
  }

  /**
   * {@inheritdoc}
   */
  public function setBaseUrl($url) {
    $this->baseUrl = $url;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function setUserAgent($userAgent, $includeDefault = false) {
    if ($includeDefault) {
      $userAgent .= ' ' . Utils::getDefaultUserAgent();
    }
    $this->userAgent = $userAgent;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function get($uri = null, $headers = null, $body = null) {
    return $this
      ->createRequest('GET', $uri, $headers, $body);
  }

  /**
   * {@inheritdoc}
   */
  public function head($uri = null, $headers = null) {
    return $this
      ->createRequest('HEAD', $uri, $headers);
  }

  /**
   * {@inheritdoc}
   */
  public function delete($uri = null, $headers = null, $body = null) {
    return $this
      ->createRequest('DELETE', $uri, $headers, $body);
  }

  /**
   * {@inheritdoc}
   */
  public function put($uri = null, $headers = null, $body = null) {
    return $this
      ->createRequest('PUT', $uri, $headers, $body);
  }

  /**
   * {@inheritdoc}
   */
  public function patch($uri = null, $headers = null, $body = null) {
    return $this
      ->createRequest('PATCH', $uri, $headers, $body);
  }

  /**
   * {@inheritdoc}
   */
  public function post($uri = null, $headers = null, $postBody = null) {
    return $this
      ->createRequest('POST', $uri, $headers, $postBody);
  }

  /**
   * {@inheritdoc}
   */
  public function options($uri = null) {
    return $this
      ->createRequest('OPTIONS', $uri);
  }

  /**
   * {@inheritdoc}
   */
  public function send($requests) {
    $curlMulti = $this
      ->getCurlMulti();
    $multipleRequests = !$requests instanceof RequestInterface;
    if (!$multipleRequests) {
      $requests = array(
        $requests,
      );
    }
    foreach ($requests as $request) {
      $curlMulti
        ->add($request);
    }
    try {
      $curlMulti
        ->send();
    } catch (ExceptionCollection $e) {
      throw $multipleRequests ? $e : $e
        ->getFirst();
    }
    if (!$multipleRequests) {
      return end($requests)
        ->getResponse();
    }
    else {
      return array_map(function ($request) {
        return $request
          ->getResponse();
      }, $requests);
    }
  }

  /**
   * {@inheritdoc}
   */
  public function setCurlMulti(CurlMultiInterface $curlMulti) {
    $this->curlMulti = $curlMulti;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function getCurlMulti() {
    if (!$this->curlMulti) {
      $this->curlMulti = CurlMulti::getInstance();
    }
    return $this->curlMulti;
  }

  /**
   * {@inheritdoc}
   */
  public function setRequestFactory(RequestFactoryInterface $factory) {
    $this->requestFactory = $factory;
    return $this;
  }

  /**
   * Prepare a request to be sent from the Client by adding client specific behaviors and properties to the request.
   *
   * @param RequestInterface $request Request to prepare for the client
   *
   * @return RequestInterface
   */
  protected function prepareRequest(RequestInterface $request) {
    $request
      ->setClient($this);

    // Add any curl options to the request
    if ($options = $this->config
      ->get(self::CURL_OPTIONS)) {
      $request
        ->getCurlOptions()
        ->merge(CurlHandle::parseCurlConfig($options));
    }

    // Add request parameters to the request
    if ($options = $this->config
      ->get(self::REQUEST_PARAMS)) {
      $request
        ->getParams()
        ->merge($options);
    }

    // Attach client observers to the request
    $request
      ->setEventDispatcher(clone $this
      ->getEventDispatcher());
    $this
      ->dispatch('client.create_request', array(
      'client' => $this,
      'request' => $request,
    ));
    return $request;
  }

}