LanguageManager.php

<?php

/**
 * @file
 * Definition of Drupal\Core\Language\LanguageManager.
 */
namespace Drupal\Core\Language;

use Symfony\Component\HttpFoundation\Request;

/**
 * Class responsible for initializing each language type.
 *
 * This service is dependent on the 'request' service and can therefore pass the
 * Request object to the code that deals with each particular language type.
 * This means the Request can be used directly for things like URL-based
 * language negotiation.
 */
class LanguageManager {
  private $request;
  private $languages;
  public function __construct(Request $request = NULL) {
    $this->request = $request;
  }
  public function getLanguage($type) {
    if (isset($this->languages[$type])) {
      return $this->languages[$type];
    }

    // @todo Objectify the language system so that we don't have to do this.
    if (language_multilingual()) {
      include_once DRUPAL_ROOT . '/core/includes/language.inc';
      $this->languages[$type] = language_types_initialize($type, $this->request);
    }
    else {
      $this->languages[$type] = language_default();
    }
    return $this->languages[$type];
  }
  public function reset($type = NULL) {
    if (!isset($type)) {
      $this->languages = array();
    }
    elseif (isset($this->languages[$type])) {
      unset($this->languages[$type]);
    }
  }

}