term_exists( int|string $term, string $taxonomy = '', int $parent_term = null )
Determines whether a taxonomy term exists.
Description
Formerly is_term(), introduced in 2.3.0.
For more information on this and similar theme functions, check out the Conditional Tags article in the Theme Developer Handbook.
Parameters
- $term
-
(Required) The term to check. Accepts term ID, slug, or name.
- $taxonomy
-
(Optional) The taxonomy name to use.
Default value: ''
- $parent_term
-
(Optional) ID of parent term under which to confine the exists search.
Default value: null
Return
(mixed) Returns null if the term does not exist.<br> Returns the term ID if no taxonomy is specified and the term ID exists.<br> Returns an array of the term ID and the term taxonomy ID if the taxonomy is specified and the pairing exists.<br> Returns 0 if term ID 0 is passed to the function.
Source
File: wp-includes/taxonomy.php
function term_exists( $term, $taxonomy = '', $parent = null ) {
global $wpdb;
$select = "SELECT term_id FROM $wpdb->terms as t WHERE ";
$tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";
if ( is_int($term) ) {
if ( 0 == $term )
return 0;
$where = 't.term_id = %d';
if ( !empty($taxonomy) )
return $wpdb->get_row( $wpdb->prepare( $tax_select . $where . " AND tt.taxonomy = %s", $term, $taxonomy ), ARRAY_A );
else
return $wpdb->get_var( $wpdb->prepare( $select . $where, $term ) );
}
$term = trim( wp_unslash( $term ) );
$slug = sanitize_title( $term );
$where = 't.slug = %s';
$else_where = 't.name = %s';
$where_fields = array($slug);
$else_where_fields = array($term);
$orderby = 'ORDER BY t.term_id ASC';
$limit = 'LIMIT 1';
if ( !empty($taxonomy) ) {
if ( is_numeric( $parent ) ) {
$parent = (int) $parent;
$where_fields[] = $parent;
$else_where_fields[] = $parent;
$where .= ' AND tt.parent = %d';
$else_where .= ' AND tt.parent = %d';
}
$where_fields[] = $taxonomy;
$else_where_fields[] = $taxonomy;
if ( $result = $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $where AND tt.taxonomy = %s $orderby $limit", $where_fields), ARRAY_A) )
return $result;
return $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $else_where AND tt.taxonomy = %s $orderby $limit", $else_where_fields), ARRAY_A);
}
if ( $result = $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $where $orderby $limit", $where_fields) ) )
return $result;
return $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $else_where $orderby $limit", $else_where_fields) );
}
Changelog
Version | Description |
---|---|
6.0.0 | Converted to use get_terms() . |
3.0.0 | Introduced. |