learnosity-1.0.x-dev/src/Controller/LearnosityEventController.php

<?php

namespace Drupal\learnosity\Controller;

use Drupal\learnosity\Event\LearnosityEvent;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Controller\ControllerBase;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\RequestStack;

/**
 * Dispatches Drupal events from Learnosity events.
 */
class LearnosityEventController extends ControllerBase implements ContainerInjectionInterface {

  /**
   * The request stack service.
   *
   * @var \Symfony\Component\HttpFoundation\RequestStack
   */
  protected $request;

  /**
   * The event dispatcher service.
   *
   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
   */
  protected $eventDispatcher;

  /**
   * LearnosityEventController constructor.
   *
   * @param \Symfony\Component\HttpFoundation\RequestStack $request
   *   The request stack service.
   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
   *   The event dispatcher service.
   */
  public function __construct(RequestStack $request, EventDispatcherInterface $event_dispatcher) {
    $this->request = $request;
    $this->eventDispatcher = $event_dispatcher;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('request_stack'),
      $container->get('event_dispatcher'),
    );
  }

  /**
   * Fetch and process the passed query parameters.
   *
   * @return array
   *   The associative array of contextual values.
   *
   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
   */
  protected function processContext() {
    // @todo: Make this more robust.
    $context = [];
    $params = $this->request->getCurrentRequest()->query->all();
    if (!empty($params)) {
      foreach ($params as $key => $param) {
        if ($key != '_wrapper_format') {
          $context[$key] = $param;
        }
      }
    }

    return $context;
  }

  /**
   * Dispatches an event from Learnosity.
   *
   * @return \Drupal\Core\Ajax\AjaxResponse
   *   The ajax response.
   *
   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
   */
  public function dispatchEvent($name) {

    // Parse the name. It should only have colons.
    $name = str_replace('-', ':', $name);

    // We are just dispatching an event, we are not executing anything else.
    $context = $this->processContext();

    $event = new LearnosityEvent($name, $context);
    $dispatch = $this->eventDispatcher->dispatch($event, 'learnosity.' . $name);

    // Check to see if any subscribers return a response. If they do then use
    // that. Otherwise default to an empty ajax response.
    $response = $dispatch->getResponse();
    if (empty($response)) {
      $response = new AjaxResponse();
    }

    return $response;
  }

}