wp-includes/taxonomy.php:2810Creates term and taxonomy relationships.
$object_idint$termsstring|int|array$taxonomystring$appendbooloptionalfalsearray|WP_Error3 hooks fire while wp_set_object_terms() runs, in this order:
Fires immediately before an object-term relationship is added.
Fires immediately after an object-term relationship is added.
Fires after an object's terms have been set.
function wp_set_object_terms( $object_id, $terms, $taxonomy, $append = false ) { global $wpdb; $object_id = (int) $object_id; if ( ! taxonomy_exists( $taxonomy ) ) { return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) ); } if ( empty( $terms ) ) { $terms = array(); } elseif ( ! is_array( $terms ) ) { $terms = array( $terms ); } if ( ! $append ) { $old_tt_ids = wp_get_object_terms( $object_id, $taxonomy, array( 'fields' => 'tt_ids', 'orderby' => 'none', 'update_term_meta_cache' => false, ) ); } else { $old_tt_ids = array(); } $tt_ids = array(); $new_tt_ids = array(); foreach ( (array) $terms as $term ) { if ( '' === trim( $term ) ) { continue; } $term_info = term_exists( $term, $taxonomy ); if ( ! $term_info ) { // Skip if a non-existent term ID is passed. if ( is_int( $term ) ) { continue; } $term_info = wp_insert_term( $term, $taxonomy ); } if ( is_wp_error( $term_info ) ) { return $term_info; } $tt_id = $term_info['term_taxonomy_id']; $tt_ids[] = $tt_id; if ( $wpdb->get_var( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id = %d", $object_id, $tt_id ) ) ) { continue; } /** * Fires immediately before an object-term relationship is added. * * @since 2.9.0 * @since 4.7.0 Added the `$taxonomy` parameter. * * @param int $object_id Object ID. * @param int $tt_id Term taxonomy ID. * @param string $taxonomy Taxonomy slug. */ do_action( 'add_term_relationship', $object_id, $tt_id, $taxonomy ); $wpdb->insert( $wpdb->term_relationships, array( 'object_id' => $object_id, 'term_taxonomy_id' => $tt_id, ) ); /**Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/taxonomy.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.