Open the notification URL when a notification is clicked while the app is already open

Events.php

@@ -7,7 +7,7 @@
 use humhub\modules\fcmPush\components\NotificationTargetProvider;
 use humhub\modules\fcmPush\helpers\MobileAppHelper;
 use humhub\modules\fcmPush\helpers\WebAppHelper;
-use humhub\modules\fcmPush\services\DriverService;
+use humhub\modules\fcmPush\services\ServiceWorkerService;
 use humhub\modules\fcmPush\widgets\RegisterDeviceTokenButton;
 use humhub\modules\notification\targets\MobileTargetProvider;
 use humhub\modules\notification\widgets\NotificationSettingsForm;
@@ -43,27 +43,8 @@ public static function onServiceWorkerControllerInit($event): void
             return;
         }
 
-        $bundle = FirebaseAsset::register(Yii::$app->view);
-
-        $pushDriver = (new DriverService($module->getConfigureForm()))->getWebDriver();
-        $baseUrl = Yii::getAlias($bundle->baseUrl);
-
         // Service Worker Addons
-        $controller->additionalJs .= <<<JS
-            // Give the service worker access to Firebase Messaging.
-            importScripts('{$baseUrl}/firebase-app-compat.js');
-            importScripts('{$baseUrl}/firebase-messaging-compat.js');
-
-            firebase.initializeApp({
-                messagingSenderId: "{$pushDriver->getSenderId()}",
-                projectId: "{$module->getConfigureForm()->getJsonParam('project_id')}",
-                appId: "{$module->getConfigureForm()->firebaseAppId}",
-                apiKey: "{$module->getConfigureForm()->firebaseApiKey}",
-            });
-
-            // Initialize Firebase Cloud Messaging and get a reference to the service
-            firebase.messaging();
-JS;
+        $controller->additionalJs .= (new ServiceWorkerService($module))->getJs();
     }
 
     public static function onLayoutAddonInit($event)

docs/CHANGELOG.md

@@ -1,6 +1,10 @@
 Changelog
 =========
 
+2.2.8 (Unreleased)
+------------------
+- Fix #100: Open the notification URL when a notification is clicked while the app is already open — Firebase only focuses the window without navigating (iOS PWAs with the app already running are not covered: WebKit never dispatches the click event there)
+
 2.2.7 (July 9, 2026)
 --------------------
 - Fix #96: Notification.requestPermission() not bound to user gesture — iOS PWA push never shown

module.json

@@ -11,7 +11,7 @@
     "humhub": {
         "minVersion": "1.18"
     },
-    "version": "2.2.7",
+    "version": "2.2.8",
     "screenshots": [
         "resources/screenshot1.PNG",
         "resources/screenshot2.PNG"

resources/js/humhub.firebase.worker.js

@@ -0,0 +1,50 @@
+/**
+ * Service worker addon for FCM push notifications, appended to the PWA service
+ * worker by ServiceWorkerService before the Firebase importScripts, so the
+ * notificationclick handler below is called before Firebase's own handler.
+ */
+
+// Activate updated service workers immediately instead of waiting for all
+// app windows to close - iOS PWAs may otherwise keep an old SW for a long time.
+self.addEventListener('install', function () {
+    self.skipWaiting();
+});
+self.addEventListener('activate', function (event) {
+    event.waitUntil(self.clients.claim());
+});
+
+// Handle notification clicks ourselves, before Firebase's own handler, which
+// only focuses an already-open window without navigating it (it delegates
+// navigation to a postMessage the page never listens for).
+//
+// Known limitation (iOS/WebKit bug, iOS 17/18): when the PWA is already
+// running, iOS never dispatches notificationclick at all, so tapping a
+// notification only brings the app to the foreground without navigating.
+// This is intentionally not worked around here - no service-worker code can
+// ever see that tap. See https://github.com/humhub/fcm-push/pull/99 for an
+// exploration of a page-side heuristic covering that case.
+self.addEventListener('notificationclick', function (event) {
+    const fcmMsg = event.notification && event.notification.data && event.notification.data.FCM_MSG;
+    const url = fcmMsg && ((fcmMsg.fcmOptions && fcmMsg.fcmOptions.link) || (fcmMsg.data && fcmMsg.data.url));
+    if (!url) {
+        return; // Not one of our notifications - leave it to Firebase's handler
+    }
+
+    // Take over completely: prevent Firebase's handler from running.
+    event.stopImmediatePropagation();
+    event.notification.close();
+
+    event.waitUntil(
+        self.clients.matchAll({type: 'window', includeUncontrolled: true}).then(function (clientList) {
+            // matchAll() returns window clients most-recently-focused first.
+            const client = clientList.find(function (c) { return 'navigate' in c; });
+            if (!client) {
+                return self.clients.openWindow(url);
+            }
+            return Promise.resolve(client.focus())
+                .catch(function () { return client; })
+                .then(function (c) { return (c || client).navigate(url); })
+                .catch(function () { return self.clients.openWindow(url); });
+        })
+    );
+});

services/ServiceWorkerService.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace humhub\modules\fcmPush\services;
+
+use humhub\modules\fcmPush\assets\FirebaseAsset;
+use humhub\modules\fcmPush\Module;
+use Yii;
+
+/**
+ * Builds the JavaScript appended to the PWA service worker
+ * (see Events::onServiceWorkerControllerInit()).
+ */
+class ServiceWorkerService
+{
+    public function __construct(private Module $module)
+    {
+    }
+
+    public function getJs(): string
+    {
+        $bundle = FirebaseAsset::register(Yii::$app->view);
+        $baseUrl = Yii::getAlias($bundle->baseUrl);
+
+        $configureForm = $this->module->getConfigureForm();
+        $pushDriver = (new DriverService($configureForm))->getWebDriver();
+
+        // Notification click handling (must be registered before the Firebase importScripts)
+        $js = file_get_contents(dirname(__DIR__) . '/resources/js/humhub.firebase.worker.js');
+
+        // Give the service worker access to Firebase Messaging.
+        $js .= <<<JS
+            importScripts('{$baseUrl}/firebase-app-compat.js');
+            importScripts('{$baseUrl}/firebase-messaging-compat.js');
+
+            firebase.initializeApp({
+                messagingSenderId: "{$pushDriver->getSenderId()}",
+                projectId: "{$configureForm->getJsonParam('project_id')}",
+                appId: "{$configureForm->firebaseAppId}",
+                apiKey: "{$configureForm->firebaseApiKey}",
+            });
+
+            // Initialize Firebase Cloud Messaging and get a reference to the service
+            firebase.messaging();
+JS;
+
+        return $js;
+    }
+}