/**
* Checks the given subset of the post hierarchy for hierarchy loops.
* Prevents loops from forming and breaks those that it finds.
*
* Attached to the nxt_insert_post_parent filter.
*
* @since 3.1.0
* @uses nxt_find_hierarchy_loop()
*
* @param int $post_parent ID of the parent for the post we're checking.
* @parem int $post_ID ID of the post we're checking.
*
* @return int The new post_parent for the post.
*/
function nxt_check_post_hierarchy_for_loops($post_parent, $post_ID)
{
// Nothing fancy here - bail
if (!$post_parent) {
return 0;
}
// New post can't cause a loop
if (empty($post_ID)) {
return $post_parent;
}
// Can't be its own parent
if ($post_parent == $post_ID) {
return 0;
}
// Now look for larger loops
if (!($loop = nxt_find_hierarchy_loop('nxt_get_post_parent_id', $post_ID, $post_parent))) {
return $post_parent;
}
// No loop
// Setting $post_parent to the given value causes a loop
if (isset($loop[$post_ID])) {
return 0;
}
// There's a loop, but it doesn't contain $post_ID. Break the loop.
foreach (array_keys($loop) as $loop_member) {
nxt_update_post(array('ID' => $loop_member, 'post_parent' => 0));
}
return $post_parent;
}
/**
* Checks the given subset of the term hierarchy for hierarchy loops.
* Prevents loops from forming and breaks those that it finds.
*
* Attached to the nxt_update_term_parent filter.
*
* @since 3.1.0
* @uses nxt_find_hierarchy_loop()
*
* @param int $parent term_id of the parent for the term we're checking.
* @param int $term_id The term we're checking.
* @param string $taxonomy The taxonomy of the term we're checking.
*
* @return int The new parent for the term.
*/
function nxt_check_term_hierarchy_for_loops($parent, $term_id, $taxonomy)
{
// Nothing fancy here - bail
if (!$parent) {
return 0;
}
// Can't be its own parent
if ($parent == $term_id) {
return 0;
}
// Now look for larger loops
if (!($loop = nxt_find_hierarchy_loop('nxt_get_term_taxonomy_parent_id', $term_id, $parent, array($taxonomy)))) {
return $parent;
}
// No loop
// Setting $parent to the given value causes a loop
if (isset($loop[$term_id])) {
return 0;
}
// There's a loop, but it doesn't contain $term_id. Break the loop.
foreach (array_keys($loop) as $loop_member) {
nxt_update_term($loop_member, $taxonomy, array('parent' => 0));
}
return $parent;
}
