More powerful/extensible notifications

- Notifications can be delivered in multiple ways (alert, email)
- Different notification types can implement interfaces to allow
themselves to be delivered in these various ways
- User preferences for each notification type/method combination are
automatically registered

src/Core/CoreServiceProvider.php

@@ -11,7 +11,6 @@ use Flarum\Core\Models\Model;
 use Flarum\Core\Models\Forum;
 use Flarum\Core\Models\User;
 use Flarum\Core\Models\Discussion;
-use Flarum\Core\Models\Notification;
 use Flarum\Core\Search\GambitManager;
 use League\Flysystem\Adapter\Local;
 
@@ -28,7 +27,6 @@ class CoreServiceProvider extends ServiceProvider
 
         $this->registerEventHandlers($events);
         $this->registerPostTypes();
-        $this->registerNotificationTypes();
         $this->registerPermissions();
         $this->registerGambits();
         $this->setupModels();
@@ -47,6 +45,8 @@ class CoreServiceProvider extends ServiceProvider
      */
     public function register()
     {
+        $this->app->register('Flarum\Core\Notifications\NotificationServiceProvider');
+
         // Register a singleton entity that represents this forum. This entity
         // will be used to check for global forum permissions (like viewing the
         // forum, registering, and starting discussions.)
@@ -81,14 +81,6 @@ class CoreServiceProvider extends ServiceProvider
             'Flarum\Core\Repositories\ActivityRepositoryInterface',
             'Flarum\Core\Repositories\EloquentActivityRepository'
         );
-        $this->app->bind(
-            'Flarum\Core\Repositories\NotificationRepositoryInterface',
-            'Flarum\Core\Repositories\EloquentNotificationRepository'
-        );
-
-        $this->app->singleton('flarum.avatars.storage', function () {
-            return new Local(__DIR__.'/../../ember/public/avatars');
-        });
 
         $this->app->when('Flarum\Core\Handlers\Commands\UploadAvatarCommandHandler')
             ->needs('League\Flysystem\FilesystemInterface')
@@ -126,16 +118,10 @@ class CoreServiceProvider extends ServiceProvider
         CommentPost::setFormatter($this->app['flarum.formatter']);
     }
 
-    public function registerNotificationTypes()
-    {
-        Notification::addType('renamed', 'Flarum\Core\Models\Discussion');
-    }
-
     public function registerEventHandlers($events)
     {
         $events->subscribe('Flarum\Core\Handlers\Events\DiscussionMetadataUpdater');
         $events->subscribe('Flarum\Core\Handlers\Events\UserMetadataUpdater');
-        $events->subscribe('Flarum\Core\Handlers\Events\DiscussionRenamedNotifier');
         $events->subscribe('Flarum\Core\Handlers\Events\EmailConfirmationMailer');
     }
 

src/Core/Handlers/Events/DiscussionRenamedNotifier.php

@@ -1,11 +1,17 @@
 <?php namespace Flarum\Core\Handlers\Events;
 
 use Flarum\Core\Events\DiscussionWasRenamed;
-use Flarum\Core\Models\Notification;
 use Flarum\Core\Models\DiscussionRenamedPost;
+use Flarum\Core\Notifications\Types\DiscussionRenamedNotification;
+use Flarum\Core\Notifications\Notifier;
 
 class DiscussionRenamedNotifier
 {
+    public function __construct(Notifier $notifier)
+    {
+        $this->notifier = $notifier;
+    }
+
     /**
      * Register the listeners for the subscriber.
      *
@@ -44,17 +50,13 @@ class DiscussionRenamedNotifier
 
     protected function sendNotification(DiscussionWasRenamed $event, DiscussionRenamedPost $post)
     {
-
-        $notification = Notification::notify(
-            $event->discussion->start_user_id,
-            'renamed',
-            $event->user->id,
-            $event->discussion->id,
-            ['number' => $post->number, 'oldTitle' => $event->oldTitle]
+        $notification = new DiscussionRenamedNotification(
+            $event->discussion->startUser,
+            $event->user,
+            $post,
+            $event->oldTitle
         );
 
-        $notification->save();
-
-        return $notification;
+        $this->notifier->send($notification);
     }
 }

src/Core/Models/Notification.php

@@ -19,14 +19,13 @@ class Notification extends Model
     protected $dates = ['time'];
 
     /**
-     * A map of notification types, as specified in the `type` column, to
-     * their subject classes.
+     *
      *
      * @var array
      */
-    protected static $types = [];
+    protected static $subjects = [];
 
-    public static function notify($userId, $type, $senderId, $subjectId, $data)
+    public static function alert($userId, $type, $senderId, $subjectId, $data)
     {
         $notification = new static;
 
@@ -95,41 +94,41 @@ class Notification extends Model
         // If the type value is null it is probably safe to assume we're eager loading
         // the relationship. When that is the case we will pass in a dummy query as
         // there are multiple types in the morph and we can't use single queries.
-        if (is_null($type = $this->$typeColumn))
-        {
+        if (is_null($type = $this->$typeColumn)) {
             return new MappedMorphTo(
-                $this->newQuery(), $this, $idColumn, null, $typeColumn, $name, static::$types
+                $this->newQuery(), $this, $idColumn, null, $typeColumn, $name, static::$subjects
             );
         }
 
         // If we are not eager loading the relationship we will essentially treat this
         // as a belongs-to style relationship since morph-to extends that class and
         // we will pass in the appropriate values so that it behaves as expected.
-        else
-        {
-            $class = static::$types[$type];
+        else {
+            $class = static::$subjects[$type];
             $instance = new $class;
 
             return new MappedMorphTo(
-                $instance->newQuery(), $this, $idColumn, $instance->getKeyName(), $typeColumn, $name, static::$types
+                $instance->newQuery(), $this, $idColumn, $instance->getKeyName(), $typeColumn, $name, static::$subjects
             );
         }
     }
 
     public static function getTypes()
     {
-        return static::$types;
+        return static::$subjects;
     }
 
     /**
-     * Register a notification type and its subject class.
+     * Register a notification type.
      *
      * @param  string $type
      * @param  string $class
      * @return void
      */
-    public static function addType($type, $class)
+    public static function registerType($class)
     {
-        static::$types[$type] = $class;
+        if ($subject = $class::getSubjectModel()) {
+            static::$subjects[$class::getType()] = $subject;
+        }
     }
 }

src/Core/Models/User.php

@@ -356,7 +356,7 @@ class User extends Model
             $defaults[$k] = $v['default'];
         }
 
-        return array_merge($defaults, (array) json_decode($value, true));
+        return array_merge($defaults, array_only((array) json_decode($value, true), array_keys(static::$preferences)));
     }
 
     public function setPreferencesAttribute($value)
@@ -372,6 +372,16 @@ class User extends Model
         ];
     }
 
+    public static function notificationPreferenceKey($type, $sender)
+    {
+        return 'notify_'.$type.'_'.$sender;
+    }
+
+    public function shouldNotify($type, $method)
+    {
+        return $this->preference(static::notificationPreferenceKey($type, $method));
+    }
+
     public function preference($key, $default = null)
     {
         return array_get($this->preferences, $key, $default);

src/Core/Notifications/NotificationServiceProvider.php

@@ -0,0 +1,35 @@
+<?php namespace Flarum\Core\Notifications;
+
+use Illuminate\Contracts\Events\Dispatcher;
+use Illuminate\Support\ServiceProvider;
+use Flarum\Core\Models\User;
+
+class NotificationServiceProvider extends ServiceProvider
+{
+    /**
+     * Bootstrap the application events.
+     *
+     * @return void
+     */
+    public function boot(Dispatcher $events)
+    {
+        $notifier = app('Flarum\Core\Notifications\Notifier');
+
+        $notifier->registerMethod('alert', 'Flarum\Core\Notifications\Senders\NotificationAlerter');
+        $notifier->registerMethod('email', 'Flarum\Core\Notifications\Senders\NotificationEmailer');
+
+        $notifier->registerType('Flarum\Core\Notifications\Types\DiscussionRenamedNotification', ['alert' => true]);
+
+        $events->subscribe('Flarum\Core\Handlers\Events\DiscussionRenamedNotifier');
+    }
+
+    public function register()
+    {
+        $this->app->bind(
+            'Flarum\Core\Repositories\NotificationRepositoryInterface',
+            'Flarum\Core\Repositories\EloquentNotificationRepository'
+        );
+
+        $this->app->singleton('Flarum\Core\Notifications\Notifier');
+    }
+}

src/Core/Notifications/Notifier.php

@@ -0,0 +1,59 @@
+<?php namespace Flarum\Core\Notifications;
+
+use Flarum\Core\Notifications\Types\Notification;
+use Flarum\Core\Models\Notification as NotificationModel;
+use Flarum\Core\Models\User;
+use Illuminate\Container\Container;
+
+class Notifier
+{
+    protected $methods = [];
+
+    protected $types = [];
+
+    protected $container;
+
+    public function __construct(Container $container)
+    {
+        $this->container = $container;
+    }
+
+    public function send(Notification $notification)
+    {
+        foreach ($this->methods as $method => $sender) {
+            $sender = $this->container->make($sender);
+            if ($notification->getRecipient()->shouldNotify($notification::getType(), $method) && $sender->compatibleWith($notification)) {
+                $sender->send($notification);
+            }
+        }
+    }
+
+    public function registerMethod($name, $class)
+    {
+        $this->methods[$name] = $class;
+    }
+
+    public function registerType($class, $defaultPreferences = [])
+    {
+        $this->types[] = $class;
+
+        NotificationModel::registerType($class);
+
+        foreach ($this->methods as $method => $sender) {
+            $sender = $this->container->make($sender);
+            if ($sender->compatibleWith($class)) {
+                User::registerPreference(User::notificationPreferenceKey($class::getType(), $method), 'boolval', array_get($defaultPreferences, $method, false));
+            }
+        }
+    }
+
+    public function getMethods()
+    {
+        return $this->methods;
+    }
+
+    public function getTypes()
+    {
+        return $this->types;
+    }
+}

src/Core/Notifications/Senders/NotificationAlerter.php

@@ -0,0 +1,25 @@
+<?php namespace Flarum\Core\Notifications\Senders;
+
+use Flarum\Core\Notifications\Types\Notification;
+use Flarum\Core\Models\Notification as NotificationModel;
+use ReflectionClass;
+
+class NotificationAlerter implements NotificationSender
+{
+    public function send(Notification $notification)
+    {
+        $model = NotificationModel::alert(
+            $notification->getRecipient()->id,
+            $notification::getType(),
+            $notification->getSender()->id,
+            $notification->getSubject()->id,
+            $notification->getAlertData()
+        );
+        $model->save();
+    }
+
+    public function compatibleWith($className)
+    {
+        return (new ReflectionClass($className))->implementsInterface('Flarum\Core\Notifications\Types\AlertableNotification');
+    }
+}

src/Core/Notifications/Senders/NotificationEmailer.php

@@ -0,0 +1,29 @@
+<?php namespace Flarum\Core\Notifications\Senders;
+
+use Flarum\Core\Notifications\Types\Notification;
+use Flarum\Core\Models\Forum;
+use Illuminate\Mail\Mailer;
+use ReflectionClass;
+
+class NotificationEmailer implements NotificationSender
+{
+    public function __construct(Mailer $mailer, Forum $forum)
+    {
+        $this->mailer = $mailer;
+        $this->forum = $forum;
+    }
+
+    public function send(Notification $notification)
+    {
+        $this->mailer->send($notification->getEmailView(), ['notification' => $notification], function ($message) use ($notification) {
+            $recipient = $notification->getRecipient();
+            $message->to($recipient->email, $recipient->username)
+                    ->subject('['.$this->forum->title.'] '.$notification->getEmailSubject());
+        });
+    }
+
+    public function compatibleWith($class)
+    {
+        return (new ReflectionClass($class))->implementsInterface('Flarum\Core\Notifications\Types\EmailableNotification');
+    }
+}

src/Core/Notifications/Senders/NotificationSender.php

@@ -0,0 +1,10 @@
+<?php namespace Flarum\Core\Notifications\Senders;
+
+use Flarum\Core\Notifications\Types\Notification;
+
+interface NotificationSender
+{
+    public function send(Notification $notification);
+
+    public function compatibleWith($class);
+}

src/Core/Notifications/Types/AlertableNotification.php

@@ -0,0 +1,8 @@
+<?php namespace Flarum\Core\Notifications\Types;
+
+interface AlertableNotification
+{
+    public function getAlertData();
+
+    public static function getType();
+}

src/Core/Notifications/Types/DiscussionRenamedNotification.php

@@ -0,0 +1,42 @@
+<?php namespace Flarum\Core\Notifications\Types;
+
+use Flarum\Core\Models\User;
+use Flarum\Core\Models\DiscussionRenamedPost;
+
+class DiscussionRenamedNotification extends Notification implements AlertableNotification
+{
+    public $post;
+
+    public $oldTitle;
+
+    public function __construct(User $recipient, User $sender, DiscussionRenamedPost $post, $oldTitle)
+    {
+        $this->post = $post;
+        $this->oldTitle = $oldTitle;
+
+        parent::__construct($recipient, $sender);
+    }
+
+    public function getSubject()
+    {
+        return $this->post->discussion;
+    }
+
+    public function getAlertData()
+    {
+        return [
+            'number'   => $this->post->number,
+            'oldTitle' => $this->oldTitle
+        ];
+    }
+
+    public static function getType()
+    {
+        return 'discussionRenamed';
+    }
+
+    public static function getSubjectModel()
+    {
+        return 'Flarum\Core\Models\Discussion';
+    }
+}

src/Core/Notifications/Types/EmailableNotification.php

@@ -0,0 +1,8 @@
+<?php namespace Flarum\Core\Notifications\Types;
+
+interface EmailableNotification
+{
+    public function getEmailView();
+
+    public function getEmailSubject();
+}

src/Core/Notifications/Types/Notification.php

@@ -0,0 +1,36 @@
+<?php namespace Flarum\Core\Notifications\Types;
+
+use Flarum\Core\Models\User;
+
+abstract class Notification
+{
+    protected $recipient;
+
+    protected $sender;
+
+    public function __construct(User $recipient, User $sender)
+    {
+        $this->recipient = $recipient;
+        $this->sender = $sender;
+    }
+
+    public function getRecipient()
+    {
+        return $this->recipient;
+    }
+
+    public function getSender()
+    {
+        return $this->sender;
+    }
+
+    public static function getType()
+    {
+        return null;
+    }
+
+    public static function getSubjectModel()
+    {
+        return null;
+    }
+}