think\Model::trigger PHP Method

    protected function trigger($event, &$params)
    {
        if (isset(self::$event[$this->class][$event])) {
            foreach (self::$event[$this->class][$event] as $callback) {
                if (is_callable($callback)) {
                    $result = call_user_func_array($callback, [&$params]);
                    if (false === $result) {
                        return false;
                    }
                }
            }
        }
        return true;
    }