PHP函数钩子怎么设计_PHP函数钩子实现插件机制

class Hook {
    private static $actions = [];
    private static $filters = [];

    // 注册动作钩子
    public static function add_action($tag, $callback) {
        self::$actions[$tag][] = $callback;
    }

    // 触发动作钩子
    public static function do_action($tag, ...$args) {
        if (isset(self::$actions[$tag])) {
            foreach (self::$actions[$tag] as $callback) {
                call_user_func($callback, ...$args);
            }
        }
    }

    // 注册过滤钩子
    public static function add_filter($tag, $callback) {
        self::$filters[$tag][] = $callback;
    }

    // 应用过滤钩子（返回处理后的值）
    public static function apply_filters($tag, $value) {
        if (isset(self::$filters[$tag])) {
            foreach (self::$filters[$tag] as $callback) {
                $value = call_user_func($callback, $value);
            }
        }
        return $value;
    }
}

// 插件1：发送欢迎邮件
Hook::add_action('user_registered', function($email) {
    echo "已向 {$email} 发送欢迎邮件。\n";
});

// 插件2：记录日志
Hook::add_action('user_registered', function($email) {
    error_log("用户 {$email} 已注册。");
});

// 插件3：过滤用户名，防止敏感词
Hook::add_filter('sanitize_username', function($username) {
    return str_replace(['admin', 'root'], '', $username);
});

// 核心逻辑调用
$username = "admin_tom";
$safe_name = Hook::apply_filters('sanitize_username', $username);

echo "净化后的用户名: " . $safe_name . "\n"; // 输出: _tom

$email = "tom@example.com";
Hook::do_action('user_registered', $email);