我有一个为自定义帖子类型存储的ID数组；服务；。其中有些是父ID，有些是子ID。
So“；service"E；此处的帖子类型是分层的。
现在，从这个ID数组中，我想以如下格式列出页面：
它们按帖子标题升序排序。
它们列在父项中；子模式如下：
Service 1
A Child
B Child
Service 2
X Child
Y Child
Service 3
由于数组包含任何ID，如果数组中有子ID，但父ID不是，则
show the parent post automatically.
到目前为止，我已经实现了以下代码：
$args = array(
\'post_type\' => array( \'service\' ),
\'posts_per_page\' => \'-1\',
\'orderby\' => \'title\',
\'order\' => \'ASC\',
\'post__in\' => $service_ids_array,
);
$all_services = new WP_Query( $args );
但是，这只是从按标题排序的ID数组中获取所有服务。
这是我试图实现的逻辑，但如果有更好的解决方案，我很乐意使用它。
所以我的逻辑是，从根级别的数组中获取所有帖子。因此父ID=0。之后，我运行这些ID的循环，并在循环中检查它们的子ID是否存在于$service_ids_array 或者不是。并显示它们是否存在。
但是如果数组中只有子ID呢？在这种情况下，这种逻辑将不会成功。
SO网友:Antti Koskinen
我认为您只需要循环这个循环，首先构建一个助手数组来包含层次结构，然后使用它来打印出任何必要的html。将生成的助手数组缓存到瞬态可能是一个节省处理时间的好主意。
// is there a transient?
$transient = get_transient( "parent_children_ids_{$post_id}" );
if ( ! $transient ) {
// initial query
$all_services = new WP_Query( $args );
// first sort found posts to a helper associative array
$posts_by_id = array();
foreach ($all_services->posts as $service) {
$posts_by_id[$service->ID]$service;
}
// create hierarchy array
$parent_children_ids = array();
// track parents IDs that are not in found posts
$missing_parent_ids = array();
// WP_Query by default returns array of WP_Post objects
// WP_Post has a property post_parent, which is the ID of the parent post, if such is set
foreach ($all_services->posts as $service) {
// add parents as top level keys
if ( ! $service->post_parent ) {
if ( ! isset($parent_children_ids[$service->ID]) ) {
$parent_children_ids[$service->ID] = array();
}
continue;
}
// add the parent to the array, if it hasn\'t been added already
if ( ! isset( $parent_children_ids[$service->post_parent] ) ) {
$parent_children_ids[$service->post_parent] = array();
}
// should the parent be queried
if ( ! isset( $posts_by_id[$service->post_parent] ) ) {
$missing_parent_ids[] = $service->post_parent;
}
// append the post to the child array
$parent_children_ids[$service->post_parent][] = $service->ID;
}
// query the missing parent posts
if ( $missing_parent_ids ) {
$missing_parents = new WP_Query(\'post__in\' => $missing_parent_ids);
// push the found posts to the posts helper array
foreach ($missing_parents->posts as $service) {
$posts_by_id[$service->ID]$service;
}
}
// do some further sorting, if needed..
// perhaps save the $parent_children_ids to an transient
// to skip the previous processing for a suitable length of time
// remember to clear the transient when the source data changes to have the transient rebuilt
set_transient( "parent_children_ids_{$post_id}", $parent_children_ids, DAY_IN_SECONDS );
} else {
$parent_children_ids = $transient;
}
// loop the parents and chilrend array
foreach ($parent_children_ids as $parent_id => $child_ids) {
$parent = $posts_by_id[$parent_id];
// parent code..
foreach ($child_ids as $child_id) {
$child = $posts_by_id[$child_id];
// child code...
}
}
