wp-includes/nav-menu-template.php:327Adds the class property classes for the current context, if applicable.
function _wp_menu_item_classes_by_context( &$menu_items ) { global $wp_query, $wp_rewrite; $queried_object = $wp_query->get_queried_object(); $queried_object_id = (int) $wp_query->queried_object_id; $active_object = ''; $active_ancestor_item_ids = array(); $active_parent_item_ids = array(); $active_parent_object_ids = array(); $possible_taxonomy_ancestors = array(); $possible_object_parents = array(); $home_page_id = (int) get_option( 'page_for_posts' ); if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) { foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) { if ( is_taxonomy_hierarchical( $taxonomy ) ) { $term_hierarchy = _get_term_hierarchy( $taxonomy ); $terms = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) ); if ( is_array( $terms ) ) { $possible_object_parents = array_merge( $possible_object_parents, $terms ); $term_to_ancestor = array(); foreach ( (array) $term_hierarchy as $ancestor => $descendents ) { foreach ( (array) $descendents as $desc ) { $term_to_ancestor[ $desc ] = $ancestor; } } foreach ( $terms as $desc ) { do { $possible_taxonomy_ancestors[ $taxonomy ][] = $desc; if ( isset( $term_to_ancestor[ $desc ] ) ) { $_desc = $term_to_ancestor[ $desc ]; unset( $term_to_ancestor[ $desc ] ); $desc = $_desc; } else { $desc = 0; } } while ( ! empty( $desc ) ); } } } } } elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) { $term_hierarchy = _get_term_hierarchy( $queried_object->taxonomy ); $term_to_ancestor = array(); foreach ( (array) $term_hierarchy as $ancestor => $descendents ) { foreach ( (array) $descendents as $desc ) { $term_to_ancestor[ $desc ] = $ancestor; } } $desc = $queried_object->term_id; do { $possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc; if ( isset( $term_to_ancestor[ $desc ] ) ) { $_desc = $term_to_ancestor[ $desc ]; unset( $term_to_ancestor[ $desc ] ); $desc = $_desc; } else { $desc = 0; } } while ( ! empty( $desc ) ); } $possible_object_parents = array_filter( $possible_object_parents ); $front_page_url = home_url(); $front_page_id = (int) get_option( 'page_on_front' ); $privacy_policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' ); foreach ( (array) $menu_items as $key => $menu_item ) { $menu_items[ $key ]->current = false; $classes = (array) $menu_item->classes; $classes[] = 'menu-item'; $classes[] = 'menu-item-type-' . $menu_item->type; $classes[] = 'menu-item-object-' . $menu_item->object; // This menu item is set as the 'Front Page'.Introduced in 3.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/nav-menu-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.