/**
* Add activity data to database.
* @param Entity $entity
* @param $activityKey
* @param int $bookId
* @param bool $extra
*/
public function add(Entity $entity, $activityKey, $bookId = 0, $extra = false)
{
$this->activity->user_id = $this->user->id;
$this->activity->book_id = $bookId;
$this->activity->key = strtolower($activityKey);
if ($extra !== false) {
$this->activity->extra = $extra;
}
$entity->activity()->save($this->activity);
$this->setNotification($activityKey);
}