我如何解决错误代码compact（）：未定义的变量：subject

Question

我一直收到此错误，但我不知道问题出在哪里，尽管我遵循了[指南] [1]中的所有步骤

Cakephp 2.x
compact() [<a href='http://php.net/function.compact'>function.compact</a>]:
Undefined variable: subject [CORE\Cake\Utility\ObjectCollection.php, line 128]

启用了重写模块

请检查以下代码，我正在使用cakephp 2版本

尝试按照本教程进行操作，但仍然出现相同的错误

public function trigger($callback, $params = array(), $options = array()) {
        if (empty($this->_enabled)) {
            return true;
        }
        if ($callback instanceof CakeEvent) {
            $event = $callback;
            if (is_array($event->data)) {
                $params =& $event->data;
            }
            if (empty($event->omitSubject)) {
                $subject = $event->subject();
            }

            foreach (array('break', 'breakOn', 'collectReturn', 'modParams') as $opt) {
                if (isset($event->{$opt})) {
                    $options[$opt] = $event->{$opt};
                }
            }
            $parts = explode('.', $event->name());
            $callback = array_pop($parts);
        }
        $options += array(
            'break' => false,
            'breakOn' => false,
            'collectReturn' => false,
            'modParams' => false
        );
        $collected = array();
        $list = array_keys($this->_enabled);
        if ($options['modParams'] !== false && !isset($params[$options['modParams']])) {
            throw new CakeException(__d('cake_dev', 'Cannot use modParams with indexes that do not exist.'));
        }

        $result = null;
        foreach ($list as $name) {
            $result = call_user_func_array(array($this->_loaded[$name], $callback), compact('subject') + $params);
            if ($options['collectReturn'] === true) {
                $collected[] = $result;
            }
            if ($options['break'] && ($result === $options['breakOn'] ||
                (is_array($options['breakOn']) && in_array($result, $options['breakOn'], true)))
            ) {
                return $result;
            } elseif ($options['modParams'] !== false && !in_array($result, array(true, false, null), true)) {
                $params[$options['modParams']] = $result;
            }
        }
        if ($options['modParams'] !== false) {
            return $params[$options['modParams']];
        }
        return $options['collectReturn'] ? $collected : $result;
    }