Use a notification driver with the new channel extender

extend.php

@@ -9,10 +9,10 @@
 
 use Flarum\Api\Event\Serializing;
 use Flarum\Extend;
-use Flarum\Notification\Event\Sending;
 use Flarum\Post\Event\Posted;
 use Flarum\Pusher\Api\Controller\AuthController;
 use Flarum\Pusher\Listener;
+use Flarum\Pusher\PusherNotificationDriver;
 use Flarum\Settings\SettingsRepositoryInterface;
 use Illuminate\Contracts\Container\Container;
 use Illuminate\Contracts\Events\Dispatcher;
@@ -30,6 +30,9 @@
 
     new Extend\Locales(__DIR__.'/locale'),
 
+    (new Extend\Notification())
+        ->driver('pusher', PusherNotificationDriver::class),
+
     function (Dispatcher $events, Container $container) {
         $container->bind(Pusher::class, function ($app) {
             $settings = $app->make(SettingsRepositoryInterface::class);
@@ -49,7 +52,6 @@ function (Dispatcher $events, Container $container) {
         });
 
         $events->listen(Posted::class, Listener\PushNewPost::class);
-        $events->listen(Sending::class, Listener\PushNotification::class);
         $events->listen(Serializing::class, Listener\AddPusherApi::class);
     },
 ];

src/PusherNotificationDriver.php

@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Pusher;
+
+use Flarum\Notification\Blueprint\BlueprintInterface;
+use Flarum\Notification\Driver\NotificationDriverInterface;
+use Illuminate\Contracts\Queue\Queue;
+
+class PusherNotificationDriver implements NotificationDriverInterface
+{
+    /**
+     * @var Queue
+     */
+    protected $queue;
+
+    public function __construct(Queue $queue)
+    {
+        $this->queue = $queue;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function send(BlueprintInterface $blueprint, array $users): void
+    {
+        if (count($users)) {
+            $this->queue->push(new SendPusherNotificationsJob($blueprint, $users));
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function registerType(string $blueprintClass, array $driversEnabledByDefault): void
+    {
+        // ...
+    }
+}

src/SendPusherNotificationsJob.php

@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Pusher;
+
+use Flarum\Notification\Blueprint\BlueprintInterface;
+use Flarum\Queue\AbstractJob;
+use Flarum\User\User;
+use Pusher;
+
+class SendPusherNotificationsJob extends AbstractJob
+{
+    /**
+     * @var BlueprintInterface
+     */
+    private $blueprint;
+
+    /**
+     * @var User[]
+     */
+    private $recipients;
+
+    public function __construct(BlueprintInterface $blueprint, array $recipients)
+    {
+        $this->blueprint = $blueprint;
+        $this->recipients = $recipients;
+    }
+
+    public function handle(Pusher $pusher)
+    {
+        foreach ($this->recipients as $user) {
+            if ($user->shouldAlert($this->blueprint::getType())) {
+                $pusher->trigger('private-user'.$user->id, 'notification', null);
+            }
+        }
+    }
+}