* Taxonomy API: WP_Taxonomy class
* Core class used for interacting with taxonomies.
final class WP_Taxonomy {
* Name of the taxonomy shown in the menu. Usually plural.
* Labels object for this taxonomy.
* If not set, tag labels are inherited for non-hierarchical types
* and category labels for hierarchical ones.
* @see get_taxonomy_labels()
* A short descriptive summary of what the taxonomy is for.
public $description = '';
* Whether a taxonomy is intended for use publicly either via the admin interface or by front-end users.
* Whether the taxonomy is publicly queryable.
public $publicly_queryable = true;
* Whether the taxonomy is hierarchical.
public $hierarchical = false;
* Whether to generate and allow a UI for managing terms in this taxonomy in the admin.
* Whether to show the taxonomy in the admin menu.
* If true, the taxonomy is shown as a submenu of the object type menu. If false, no menu is shown.
public $show_in_menu = true;
* Whether the taxonomy is available for selection in navigation menus.
public $show_in_nav_menus = true;
* Whether to list the taxonomy in the tag cloud widget controls.
public $show_tagcloud = true;
* Whether to show the taxonomy in the quick/bulk edit panel.
public $show_in_quick_edit = true;
* Whether to display a column for the taxonomy on its post type listing screens.
public $show_admin_column = false;
* The callback function for the meta box display.
public $meta_box_cb = null;
* The callback function for sanitizing taxonomy data saved from a meta box.
public $meta_box_sanitize_cb = null;
* An array of object types this taxonomy is registered for.
public $object_type = null;
* Capabilities for this taxonomy.
* Rewrites information for this taxonomy.
* Query var string for this taxonomy.
* Function that will be called when the count is updated.
public $update_count_callback;
* Whether this taxonomy should appear in the REST API.
* Default false. If true, standard endpoints will be registered with
* respect to $rest_base and $rest_controller_class.
* @var bool $show_in_rest
* The base path for this taxonomy's REST API endpoints.
* @var string|bool $rest_base
* The controller for this taxonomy's REST API endpoints.
* Custom controllers must extend WP_REST_Controller.
* @var string|bool $rest_controller_class
public $rest_controller_class;
* The controller instance for this taxonomy's REST API endpoints.
* Lazily computed. Should be accessed using {@see WP_Taxonomy::get_rest_controller()}.
* @var WP_REST_Controller $rest_controller
* The default term name for this taxonomy. If you pass an array you have
* to set 'name' and optionally 'slug' and 'description'.
* Whether terms in this taxonomy should be sorted in the order they are provided to `wp_set_object_terms()`.
* Use this in combination with `'orderby' => 'term_order'` when fetching terms.
* Array of arguments to automatically use inside `wp_get_object_terms()` for this taxonomy.
* Whether it is a built-in taxonomy.
* See the register_taxonomy() function for accepted arguments for `$args`.
* @global WP $wp Current WordPress environment instance.
* @param string $taxonomy Taxonomy key, must not exceed 32 characters.
* @param array|string $object_type Name of the object type for the taxonomy object.
* @param array|string $args Optional. Array or query string of arguments for registering a taxonomy.
public function __construct( $taxonomy, $object_type, $args = array() ) {
$this->set_props( $object_type, $args );
* Sets taxonomy properties.
* See the register_taxonomy() function for accepted arguments for `$args`.
* @param array|string $object_type Name of the object type for the taxonomy object.
* @param array|string $args Array or query string of arguments for registering a taxonomy.
public function set_props( $object_type, $args ) {
$args = wp_parse_args( $args );
* Filters the arguments for registering a taxonomy.
* @param array $args Array of arguments for registering a taxonomy.
* See the register_taxonomy() function for accepted arguments.
* @param string $taxonomy Taxonomy key.
* @param string[] $object_type Array of names of object types for the taxonomy.
$args = apply_filters( 'register_taxonomy_args', $args, $this->name, (array) $object_type );
'publicly_queryable' => null,
'show_in_nav_menus' => null,
'show_in_quick_edit' => null,
'show_admin_column' => false,
'meta_box_sanitize_cb' => null,
'capabilities' => array(),
'query_var' => $this->name,
'update_count_callback' => '',
'rest_controller_class' => false,
$args = array_merge( $defaults, $args );
// If not set, default to the setting for 'public'.
if ( null === $args['publicly_queryable'] ) {
$args['publicly_queryable'] = $args['public'];
if ( false !== $args['query_var'] && ( is_admin() || false !== $args['publicly_queryable'] ) ) {
if ( true === $args['query_var'] ) {
$args['query_var'] = $this->name;
$args['query_var'] = sanitize_title_with_dashes( $args['query_var'] );
// Force 'query_var' to false for non-public taxonomies.
$args['query_var'] = false;
if ( false !== $args['rewrite'] && ( is_admin() || get_option( 'permalink_structure' ) ) ) {
$args['rewrite'] = wp_parse_args(
if ( empty( $args['rewrite']['slug'] ) ) {
$args['rewrite']['slug'] = sanitize_title_with_dashes( $this->name );
// If not set, default to the setting for 'public'.
if ( null === $args['show_ui'] ) {
$args['show_ui'] = $args['public'];
// If not set, default to the setting for 'show_ui'.
if ( null === $args['show_in_menu'] || ! $args['show_ui'] ) {
$args['show_in_menu'] = $args['show_ui'];
// If not set, default to the setting for 'public'.
if ( null === $args['show_in_nav_menus'] ) {
$args['show_in_nav_menus'] = $args['public'];
// If not set, default to the setting for 'show_ui'.
if ( null === $args['show_tagcloud'] ) {
$args['show_tagcloud'] = $args['show_ui'];
// If not set, default to the setting for 'show_ui'.
if ( null === $args['show_in_quick_edit'] ) {
$args['show_in_quick_edit'] = $args['show_ui'];
'manage_terms' => 'manage_categories',
'edit_terms' => 'manage_categories',
'delete_terms' => 'manage_categories',
'assign_terms' => 'edit_posts',
$args['cap'] = (object) array_merge( $default_caps, $args['capabilities'] );
unset( $args['capabilities'] );
$args['object_type'] = array_unique( (array) $object_type );
// If not set, use the default meta box.
if ( null === $args['meta_box_cb'] ) {
if ( $args['hierarchical'] ) {
$args['meta_box_cb'] = 'post_categories_meta_box';
$args['meta_box_cb'] = 'post_tags_meta_box';
$args['name'] = $this->name;
// Default meta box sanitization callback depends on the value of 'meta_box_cb'.
if ( null === $args['meta_box_sanitize_cb'] ) {
switch ( $args['meta_box_cb'] ) {
case 'post_categories_meta_box':
$args['meta_box_sanitize_cb'] = 'taxonomy_meta_box_sanitize_cb_checkboxes';
case 'post_tags_meta_box':
$args['meta_box_sanitize_cb'] = 'taxonomy_meta_box_sanitize_cb_input';
// Default taxonomy term.
if ( ! empty( $args['default_term'] ) ) {
if ( ! is_array( $args['default_term'] ) ) {
$args['default_term'] = array( 'name' => $args['default_term'] );
$args['default_term'] = wp_parse_args(
foreach ( $args as $property_name => $property_value ) {
$this->$property_name = $property_value;
$this->labels = get_taxonomy_labels( $this );
$this->label = $this->labels->name;
* Adds the necessary rewrite rules for the taxonomy.
* @global WP $wp Current WordPress environment instance.
public function add_rewrite_rules() {
// Non-publicly queryable taxonomies should not register query vars, except in the admin.
if ( false !== $this->query_var && $wp ) {
$wp->add_query_var( $this->query_var );
if ( false !== $this->rewrite && ( is_admin() || get_option( 'permalink_structure' ) ) ) {
if ( $this->hierarchical && $this->rewrite['hierarchical'] ) {
add_rewrite_tag( "%$this->name%", $tag, $this->query_var ? "{$this->query_var}=" : "taxonomy=$this->name&term=" );
add_permastruct( $this->name, "{$this->rewrite['slug']}/%$this->name%", $this->rewrite );
* Removes any rewrite rules, permastructs, and rules for the taxonomy.
* @global WP $wp Current WordPress environment instance.
public function remove_rewrite_rules() {
if ( false !== $this->query_var ) {
$wp->remove_query_var( $this->query_var );
// Remove rewrite tags and permastructs.
if ( false !== $this->rewrite ) {
remove_rewrite_tag( "%$this->name%" );
remove_permastruct( $this->name );
* Registers the ajax callback for the meta box.