wp_nav_menu_objects循环仅对首个菜单项生效，ACF图标无法批量添加

我为WordPress菜单项创建了ACF字段，参考ACF官方文档编写代码，尝试遍历菜单项输出图标，但图标仅附加到循环中的第一个菜单项。以下是我的代码：

functions.php 代码 #

add_filter('wp_nav_menu_objects', 'icon_wp_nav_menu_objects', 10, 2);

function icon_wp_nav_menu_objects($items, $args)
{
  if ($args->theme_location == 'main-menu') {
    
    // loop
    foreach ($items as &$item) {

      // vars
      $icon = get_field('icon', $item);

      // append icon
      if ($icon) {
        $item->title .= ' <img src="' . $icon . '" width="40px">';
      }

      // return
      return $items;
    }
  }
}

执行print_r($items)得到如下结果：

Array
  (
    [1] => WP_Post Object(
      [ID] => 297[post_author] => 1[post_date] => 2023 - 08 - 21 13: 30: 30[post_date_gmt] => 2023 - 07 - 23 17: 19: 42[post_content] => [post_title] => [post_excerpt] => [post_status] => publish[comment_status] => closed[ping_status] => closed[post_password] => [post_name] => 297[to_ping] => [pinged] => [post_modified] => 2023 - 08 - 21 13: 30: 30[post_modified_gmt] => 2023 - 08 - 21 13: 30: 30[post_content_filtered] => [post_parent] => 0[guid] => http: //website.local/?p=297
      [menu_order] => 1[post_type] => nav_menu_item[post_mime_type] => [comment_count] => 0[filter] => raw[db_id] => 297[menu_item_parent] => 0[object_id] => 208[object] => page[type] => post_type[type_label] => Page[url] => http: //website.local/menu-item/
      [title] => Menu Item [target] => [attr_title] => [description] => [classes] => Array(
        [0] => [1] => menu - item[2] => menu - item - type - post_type[3] => menu - item - object - page[4] => menu - item - has - children
      )

      [xfn] => [current] => [current_item_ancestor] => [current_item_parent] =>
    )

    [2] => WP_Post Object(
      [ID] => 298[post_author] => 1[post_date] => 2023 - 08 - 21 13: 30: 30[post_date_gmt] => 2023 - 07 - 23 17: 19: 42[post_content] => [post_title] => [post_excerpt] => [post_status] => publish[comment_status] => closed[ping_status] => closed[post_password] => [post_name] => 298[to_ping] => [pinged] => [post_modified] => 2023 - 08 - 21 13: 30: 30[post_modified_gmt] => 2023 - 08 - 21 13: 30: 30[post_content_filtered] => [post_parent] => 0[guid] => http: //website.local/?p=298
      [menu_order] => 2[post_type] => nav_menu_item[post_mime_type] => [comment_count] => 0[filter] => raw[db_id] => 298[menu_item_parent] => 297[object_id] => 208[object] => page[type] => post_type[type_label] => Page[url] => http: //website.local/blog/
      [title] => Blog [target] => [attr_title] => [description] => [classes] => Array(
        [0] => [1] => menu - item[2] => menu - item - type - post_type[3] => menu - item - object - page
      )

      [xfn] => [current] => [current_item_ancestor] => [current_item_parent] =>
    )

    [3] => WP_Post Object(
      [ID] => 296[post_author] => 1[post_date] => 2023 - 08 - 21 13: 30: 30[post_date_gmt] => 2023 - 07 - 23 17: 19: 42[post_content] => [post_title] => [post_excerpt] => [post_status] => publish[comment_status] => closed[ping_status] => closed[post_password] => [post_name] => 296[to_ping] => [pinged] => [post_modified] => 2023 - 08 - 21 13: 30: 30[post_modified_gmt] => 2023 - 08 - 21 13: 30: 30[post_content_filtered] => [post_parent] => 0[guid] => http: //website.local/?p=296
      [menu_order] => 3[post_type] => nav_menu_item[post_mime_type] => [comment_count] => 0[filter] => raw[db_id] => 296[menu_item_parent] => 297[object_id] => 289[object] => page[type] => post_type[type_label] => Page[url] => http: //website.local/page/
      [title] => Page[target] => [attr_title] => [description] => [classes] => Array(
        [0] => [1] => menu - item[2] => menu - item - type - post_type[3] => menu - item - object - page
      )

      [xfn] => [current] => [current_item_ancestor] => [current_item_parent] =>
    )

    [4] => WP_Post Object(
      [ID] => 55[post_author] => 1[post_date] => 2023 - 08 - 21 13: 30: 30[post_date_gmt] => 2023 - 07 - 15 13: 46: 30[post_content] => [post_title] => How can we help ? [post_excerpt] => [post_status] => publish[comment_status] => closed[ping_status] => closed[post_password] => [post_name] => link - 1[to_ping] => [pinged] => [post_modified] => 2023 - 08 - 21 13 : 30: 30[post_modified_gmt] => 2023 - 08 - 21 13: 30: 30[post_content_filtered] => [post_parent] => 0[guid] => http: //website.local/link-1/
      [menu_order] => 4[post_type] => nav_menu_item[post_mime_type] => [comment_count] => 0[filter] => raw[db_id] => 55[menu_item_parent] => 0[object_id] => 55[object] => custom[type] => custom[type_label] => Custom Link[title] => Link [url] => https : //website.local/link/
      [target] => [attr_title] => [description] => [classes] => Array(
        [0] => [1] => menu - item[2] => menu - item - type - custom[3] => menu - item - object - custom[4] => menu - item - has - children
      )

      [xfn] => [current] => [current_item_ancestor] => [current_item_parent] =>
    )
)

请问我哪里出错了？

问题出在**return $items语句的位置错误**——它被放在了foreach循环内部。

当代码执行第一次循环时，处理完第一个菜单项后就直接返回了修改后的$items数组，循环根本没有机会处理剩下的菜单项，所以只有第一个菜单项会被添加图标。

修正后的代码需要把return $items移到循环和if判断的外面，确保所有菜单项都被遍历处理完后再返回结果：

add_filter('wp_nav_menu_objects', 'icon_wp_nav_menu_objects', 10, 2);

function icon_wp_nav_menu_objects($items, $args)
{
  if ($args->theme_location == 'main-menu') {
    
    // 遍历所有菜单项
    foreach ($items as &$item) {

      // 获取ACF图标字段
      $icon = get_field('icon', $item);

      // 如果图标存在，追加到标题后
      if ($icon) {
        $item->title .= ' <img src="' . esc_url($icon) . '" width="40px">';
      }
      
      // 循环内部不再保留return语句
    }
    // 所有菜单项处理完成后再返回
    return $items;
  }
  
  // 如果不是目标菜单，直接返回原数组
  return $items;
}

另外建议加上esc_url()函数对图标URL进行转义处理，避免潜在的安全问题和URL格式错误。

内容的提问来源于stack exchange，提问作者emilyyyyyy