Improve notification classes and move interface to core

app/Notification/ActivityStreamNotification.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Kanboard\Notification;
+
+use Kanboard\Core\Base;
+use Kanboard\Core\Notification\NotificationInterface;
+
+/**
+ * Activity Stream Notification
+ *
+ * @package  Kanboard\Notification
+ * @author   Frederic Guillot
+ */
+class ActivityStreamNotification extends Base implements NotificationInterface
+{
+    /**
+     * Send notification to a user
+     *
+     * @access public
+     * @param  array     $user
+     * @param  string    $event_name
+     * @param  array     $event_data
+     */
+    public function notifyUser(array $user, $event_name, array $event_data)
+    {
+    }
+
+    /**
+     * Send notification to a project
+     *
+     * @access public
+     * @param  array     $project
+     * @param  string    $event_name
+     * @param  array     $event_data
+     */
+    public function notifyProject(array $project, $event_name, array $event_data)
+    {
+        if ($this->userSession->isLogged()) {
+            $this->projectActivity->createEvent(
+                $project['id'],
+                $event_data['task']['id'],
+                $this->userSession->getId(),
+                $event_name,
+                $event_data
+            );
+        }
+    }
+}