旧Artisteer主题在WP6.6.2+PHP8.2下生成空菜单链接问题

我正在恢复一个被入侵的网站，原主题由Artisteer v4.3.0.60745生成。在全新本地WordPress 6.6.2（无插件）+PHP 8.2.20环境中运行时，头部和侧边栏菜单无法加载标题与链接，仅生成无标题的空href：

<ul class="art-hmenu menu-6">
    <li class="menu-item-"><a href="#"></a>
    </li>
    <li class="menu-item-"><a href="#"></a>
    </li>
    <li class="menu-item-"><a href="#"></a>
    </li>
    <li class="menu-item-"><a href="#"></a>
    </li>
    <li class="menu-item-"><a href="#"></a>
    </li>
</ul>

调试显示sorted_menu_items包含正确数据，但传入theme_MenuItem类后生成的$items均为null。相关代码片段如下：

wp-content/themes/osp5/library/navigation.php 第35行代码 #

/* custom menu */

function theme_get_list_menu($args = array()) {
    global $wp_query;
    $menu_items = wp_get_nav_menu_items($args['menu']->term_id);
    if (empty($menu_items))
        return '';
    $home_page_id = (int) get_option('page_for_posts');
    $queried_object = $wp_query->get_queried_object();
    $queried_object_id = (int) $wp_query->queried_object_id;
    $active_ID = null;

    $IdToKey = array();
    foreach ((array) $menu_items as $key => $menu_item) {
        $IdToKey[$menu_item->ID] = $key;
        if ($menu_item->object_id == $queried_object_id &&
                (
                (!empty($home_page_id) && 'post_type' == $menu_item->type && $wp_query->is_home && $home_page_id == $menu_item->object_id ) ||
                ( 'post_type' == $menu_item->type && $wp_query->is_singular ) ||
                ( 'taxonomy' == $menu_item->type && ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax ))
                )
        ) {
            $active_ID = $menu_item->ID;
        } elseif ('custom' == $menu_item->object) {
            if (theme_is_current_url($menu_item->url)) {
                $active_ID = $menu_item->ID;
            }
        }
    }

    $current_ID = $active_ID;
    while ($current_ID && isset($IdToKey[$current_ID])) {
        $activeIDs[] = $current_ID;
        $current_item = &$menu_items[$IdToKey[$current_ID]];
        $current_item->classes[] = 'active';
        $current_ID = $current_item->menu_item_parent;
    }

    $sorted_menu_items = array();
    foreach ((array) $menu_items as $key => $menu_item) {
        $sorted_menu_items[$menu_item->menu_order] = wp_setup_nav_menu_item($menu_item);
    }

    $items = array();
    foreach ($sorted_menu_items as $el) {
        $id = $el->db_id;
        $title = $el->title;
        $classes = empty($el->classes) ? array() : (array) $el->classes;
        $active = in_array('active', $classes);
        $items[] = new theme_MenuItem(array(
                    'id' => $id,
                    'active' => $active,
                    'attr' => array(
                        'title' => strip_tags(empty($el->attr_title) ? $title : $el->attr_title),
                        'target' => $el->target,
                        'rel' => $el->xfn,
                        'href' => $el->url,
                        'class' => join(' ', apply_filters('nav_menu_css_class', array_filter($classes), $el))
                    ),
                    'title' => $title,
                    'parent' => $el->menu_item_parent
                ));
    }

    $walker = new theme_MenuWalker();
    $items = apply_filters('wp_nav_menu_objects', $items, $args);
    $items = $walker->walk($items, $args);
    $items = apply_filters('wp_nav_menu_items', $items, $args);
    return apply_filters('wp_nav_menu', $items, $args);
}

第246行的theme_MenuItem类代码 #

/* menu item */

class theme_MenuItem {

    var $id;
    var $active;
    var $parent;
    var $attr;
    var $title;

    function theme_MenuItem($args = '') {
        $args = wp_parse_args($args, array(
            'id' => '',
            'active' => false,
            'parent' => 0,
            'attr' => '',
            'title' => '',
                )
        );
        $this->id = $args['id'];
        $this->active = $args['active'];
        $this->parent = $args['parent'];
        $this->attr = $args['attr'];
        $this->title = $args['title'];
    }

    function get_start($level) {
        $class = theme_get_array_value($this->attr, 'class', '');
        $class = 'menu-item-' . $this->id . (strlen($class) > 0 ? ' ' : '') . $class;
        $this->attr['class'] = ($this->active ? 'active' : null);
        $title = apply_filters('the_title', $this->title, $this->id);
        if (theme_get_option('theme_menu_trim_title')) {
            $title = theme_trim_long_str(strip_tags($title), theme_get_option($level == 0 ? 'theme_menu_trim_len' : 'theme_submenu_trim_len'));
        }
        return str_repeat("	", $level + 1)
                . '<li' . theme_prepare_attr(array('class' => $class)) . '>'
                . '<a' . theme_prepare_attr($this->attr) . '>'
                . $title
                . '</a>' . "
";
    }

    function get_end($level) {
        return str_repeat("	", $level + 1) . '</li>' . "
";
    }

}

开启WP_DEBUG后出现以下弃用警告：

Deprecated: str_contains(): Passing null to parameter #1 ($haystack) of type string is deprecated in /Applications/MAMP/htdocs/osprzemien/wp-includes/formatting.php on line 2476

Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in /Applications/MAMP/htdocs/osprzemien/wp-includes/class-wp-hook.php on line 326

问题根源 #

1. PHP 8.0+严格类型检查：原代码中传递null给字符串类型参数（如trim()、str_contains()）触发弃用警告，导致数据处理异常。
2. theme_MenuItem构造函数类型冲突：$args['attr']默认值为空字符串，但实际传入的是数组，导致属性赋值错误。
3. 未处理WP API返回的空值：新版本WP中wp_setup_nav_menu_item返回的对象属性可能为空，原代码未做兜底处理。

修复步骤 #

1. 修复theme_MenuItem构造函数 #

将'attr'默认值从空字符串改为数组，避免类型冲突：

function theme_MenuItem($args = '') {
    $args = wp_parse_args($args, array(
        'id' => '',
        'active' => false,
        'parent' => 0,
        'attr' => array(), // 修正为数组类型
        'title' => '',
            )
    );
    $this->id = $args['id'];
    $this->active = $args['active'];
    $this->parent = $args['parent'];
    $this->attr = $args['attr'];
    $this->title = $args['title'];
}

2. 给菜单属性添加空值兜底 #

在theme_get_list_menu函数中，使用空值合并运算符处理可能为空的属性：

foreach ($sorted_menu_items as $el) {
    $id = $el->db_id ?? '';
    $title = $el->title ?? '';
    $classes = empty($el->classes) ? array() : (array) $el->classes;
    $active = in_array('active', $classes);
    $items[] = new theme_MenuItem(array(
                'id' => $id,
                'active' => $active,
                'attr' => array(
                    'title' => strip_tags(empty($el->attr_title) ? $title : ($el->attr_title ?? '')),
                    'target' => $el->target ?? '',
                    'rel' => $el->xfn ?? '',
                    'href' => $el->url ?? '#',
                    'class' => join(' ', apply_filters('nav_menu_css_class', array_filter($classes), $el)) ?? ''
                ),
                'title' => $title,
                'parent' => $el->menu_item_parent ?? 0
            ));
}

3. 修复get_start方法中的空值问题 #

将null替换为空字符串，避免传递无效参数给字符串处理函数：

function get_start($level) {
    $item_id = $this->id ?? '';
    $class = theme_get_array_value($this->attr, 'class', '');
    $class = 'menu-item-' . $item_id . (strlen($class) > 0 ? ' ' : '') . $class;
    // 将null改为空字符串
    $this->attr['class'] = ($this->active ? 'active' : '');
    $title = apply_filters('the_title', $this->title ?? '', $item_id);
    if (theme_get_option('theme_menu_trim_title')) {
        $title = theme_trim_long_str(strip_tags($title), theme_get_option($level == 0 ? 'theme_menu_trim_len' : 'theme_submenu_trim_len'));
    }
    return str_repeat("	", $level + 1)
            . '<li' . theme_prepare_attr(array('class' => $class)) . '>'
            . '<a' . theme_prepare_attr($this->attr) . '>'
            . $title
            . '</a>' . "
";
}

4. 优化theme_prepare_attr函数（若存在） #

确保该函数过滤空属性值，避免生成无效HTML：

function theme_prepare_attr($attrs) {
    $output = '';
    foreach ($attrs as $key => $value) {
        if (is_string($value) && trim($value) !== '') {
            $output .= ' ' . esc_attr($key) . '="' . esc_attr($value) . '"';
        }
    }
    return $output;
}

内容的提问来源于stack exchange，提问作者krazykipa