Merge pull request #53 from froboy/DS-280-cross-domain-tracking

DS-280 feat: Add cross-domain tracking module

openy_xdt/openy_xdt.info.yml

@@ -0,0 +1,5 @@
+name: YMCA Website Services Cross-domain Tracking (XDT)
+type: module
+description: Enable cross-domain tracking through TrustedRedirectResponse based on certain cookies and domains.
+package: YMCA Website Services
+core_version_requirement: ^9 || ^10

openy_xdt/openy_xdt.services.yml

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+services:
+  openy_xdt.event_subscriber:
+    class: Drupal\openy_xdt\EventSubscriber\OpenyXdtSubscriber
+    tags:
+      - { name: event_subscriber }

openy_xdt/src/EventSubscriber/OpenyXdtSubscriber.php

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+<?php
+
+namespace Drupal\openy_xdt\EventSubscriber;
+
+use Drupal\Component\Utility\UrlHelper;
+use Drupal\Component\Utility\Xss;
+use Drupal\Core\Routing\TrustedRedirectResponse;
+use Drupal\Core\Url;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+/**
+ * Openy Cross-domain Tracking (XDT) event subscriber.
+ */
+class OpenyXdtSubscriber implements EventSubscriberInterface {
+
+  /**
+   * Kernel response event handler.
+   *
+   * @param ResponseEvent $event
+   *   Response event.
+   */
+  public function onKernelResponse(ResponseEvent $event) {
+    // Grab a cookie to decorate the response url.
+    if ($event->getResponse() instanceof TrustedRedirectResponse) {
+      // @todo Move both of these to config.
+      $cookies = ['_ga', '_gl'];
+      $domains = [];
+
+      /* @var $response TrustedRedirectResponse */
+      $response = $event->getResponse();
+      $url = $response->getTargetUrl();
+
+      // First decompose the URL into its parts as there may be existing queries.
+      $parts = UrlHelper::parse($url);
+
+      // If domains are specified AND do not match the url, do nothing.
+      if (!empty($domains) && !in_array(parse_url($parts['path'], PHP_URL_HOST), $domains)) {
+        return;
+      }
+
+      // If there is no domain specified, OR if the domain matches the url host,
+      // then merge any additional cookies into the query.
+      foreach ($cookies as $cookie) {
+        if (isset($_COOKIE[$cookie])) {
+          $parts['query'][$cookie] = Xss::filter($_COOKIE[$cookie]);
+        }
+      }
+
+      // Finally recompose the URL and convert it back to a string.
+      $newUrl = Url::fromUri($parts['path'], [
+        'query' => $parts['query'],
+        'fragment' => $parts['fragment']
+      ])->toString();
+
+      $response->setTrustedTargetUrl($newUrl);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    return [
+      KernelEvents::RESPONSE => ['onKernelResponse'],
+    ];
+  }
+
+}