get_term_children( int $term_id, string $taxonomy )
Merge all term children into a single array of their IDs.
Description
This recursive function will merge all of the children of $term into the same array of term IDs. Only useful for taxonomies which are hierarchical.
Will return an empty array if $term does not exist in $taxonomy.
Parameters
- $term_id
-
(int) (Required) ID of Term to get children.
- $taxonomy
-
(string) (Required) Taxonomy Name.
Return
(array|WP_Error) List of Term IDs. WP_Error returned if $taxonomy does not exist.
Source
File: wp-includes/taxonomy.php
function get_term_children( $term_id, $taxonomy ) {
if ( ! taxonomy_exists( $taxonomy ) ) {
return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
}
$term_id = intval( $term_id );
$terms = _get_term_hierarchy( $taxonomy );
if ( ! isset( $terms[ $term_id ] ) ) {
return array();
}
$children = $terms[ $term_id ];
foreach ( (array) $terms[ $term_id ] as $child ) {
if ( $term_id === $child ) {
continue;
}
if ( isset( $terms[ $child ] ) ) {
$children = array_merge( $children, get_term_children( $child, $taxonomy ) );
}
}
return $children;
}
Changelog
| Version | Description |
|---|---|
| 2.3.0 | Introduced. |
A Basic Example
Used to get an array of children taxonomies and write them out with links in an unordered list.
<?php $term_id = 10; $taxonomy_name = 'products'; $termchildren = get_term_children( $term_id, $taxonomy_name ); echo '<ul>'; foreach ( $termchildren as $child ) { $term = get_term_by( 'id', $child, $taxonomy_name ); echo '<li><a href="' . get_term_link( $child, $taxonomy_name ) . '">' . $term->name . '</a></li>'; } echo '</ul>'; ?>This would return something like.