我目前有一个带有WooCommerce订阅插件的WooCommerce网站。我试图在通过仪表板创建新订阅订单时添加post meta，但在订阅仍处于挂起状态时，很难保存meta。
仅当满足以下两个条件时，我才需要保存该值：
只有当帖子是通过WordPress仪表板创建的，而不是通过前端的购物车系统创建时，才应首先创建帖子
add_action( \'added_post_meta\', \'shop_sync_on_shop_subscription_save\', 10, 4 );
add_action( \'updated_post_meta\', \'shop_sync_on_shop_subscription_save\', 10, 4 );
function shop_sync_on_shop_subscription_save( $meta_id, $post_id, $meta_key, $meta_value ) {
if ( $meta_key == \'_edit_lock\' ) { // we\'ve been editing the post
if ( get_post_type( $post_id ) == \'shop_subscription\' ) { // we\'ve been editing a subscription
$remaining_issues = get_post_meta($post_id, \'_remaining_issues\');
if ($remaining_issues == "") { // we only want to update to the default 6 if this has not already been set
update_post_meta($post_id, \'_remaining_issues\', \'6\');
}
}
}
}
SO网友:Mammaltron
如果找不到键，不带第三个参数的get\\u post\\u meta（）将返回一个空数组，因此每次检查$剩余的\\u问题都会失败。
尝试
$remaining_issues = get_post_meta($post_id, \'_remaining_issues\',true);
if ($remaining_issues === false) { // we only want to update to the default 6 if this has not already been set
update_post_meta($post_id, \'_remaining_issues\', \'6\');
}
