* Core Taxonomy API

 * backward compatibility reasons), and again on the {@see 'init'} action. We must

 * avoid registering rewrite rules before the {@see 'init'} action.

 *

 * @since 2.8.0

 *

 * @global WP_Rewrite $wp_rewrite The WordPress rewrite class.

		 * Filters the post formats rewrite base.

		'capabilities' => array(

			'manage_terms' => 'manage_categories',

			'edit_terms'   => 'edit_categories',

			'delete_terms' => 'delete_categories',

			'assign_terms' => 'assign_categories',

		),

		'show_in_rest' => true,

		'rest_base' => 'categories',

		'rest_controller_class' => 'WP_REST_Terms_Controller',

		'capabilities' => array(

			'manage_terms' => 'manage_post_tags',

			'edit_terms'   => 'edit_post_tags',

			'delete_terms' => 'delete_post_tags',

			'assign_terms' => 'assign_post_tags',

		),

		'show_in_rest' => true,

		'rest_base' => 'tags',

		'rest_controller_class' => 'WP_REST_Terms_Controller',

			'back_to_items' => __( '← Back to Link Categories' ),

		'show_ui' => true,

 * Retrieves a list of registered taxonomy names or objects.

 *

 * @global array $wp_taxonomies The registered taxonomies.

 *

 * @param array  $args     Optional. An array of `key => value` arguments to match against the taxonomy objects.

 *                         Default empty array.

 * @param string $output   Optional. The type of output to return in the array. Accepts either taxonomy 'names'

 *                         or 'objects'. Default 'names'.

 * @param string $operator Optional. The logical operation to perform. Accepts 'and' or 'or'. 'or' means only

 *                         one element from the array needs to match; 'and' means all elements must match.

 *                         Default 'and'.

 * @return array A list of taxonomy names or objects.

 * Return the names or objects of the taxonomies which are registered for the requested object or object type, such as

 * a post object or post type name.

 *

 * Example:

 *

 *     $taxonomies = get_object_taxonomies( 'post' );

 *

 * This results in:

 *

 *     Array( 'category', 'post_tag' )

 * @global array $wp_taxonomies The registered taxonomies.

 *

 * @param array|string|WP_Post $object Name of the type of taxonomy object, or an object (row from posts)

 * @param string               $output Optional. The type of output to return in the array. Accepts either

 *                                     taxonomy 'names' or 'objects'. Default 'names'.

function get_object_taxonomies( $object, $output = 'names' ) {

			return get_attachment_taxonomies( $object, $output );

 * @global array $wp_taxonomies The registered taxonomies.

 *

 * @param string $taxonomy Name of taxonomy object to return.

 * @return WP_Taxonomy|false The Taxonomy Object or false if $taxonomy doesn't exist.

 * @global array $wp_taxonomies The registered taxonomies.

 *

 * @param string $taxonomy Name of taxonomy object.

 * @param string $taxonomy Name of taxonomy object.

 * @return bool Whether the taxonomy is hierarchical.

 * Creates or modifies a taxonomy object.

 *

 * Note: Do not use before the {@see 'init'} hook.

 *

 * A simple function for creating or modifying a taxonomy object based on

 * the parameters given. If modifying an existing taxonomy object, note

 * that the `$object_type` value from the original registration will be

 * overwritten.

 * @since 4.4.0 The `show_ui` argument is now enforced on the term editing screen.

 * @since 4.4.0 The `public` argument now controls whether the taxonomy can be queried on the front end.

 * @since 4.5.0 Introduced `publicly_queryable` argument.

 * @since 4.7.0 Introduced `show_in_rest`, 'rest_base' and 'rest_controller_class'

 *              arguments to register the Taxonomy in REST API.

 *

 * @param string       $taxonomy    Taxonomy key, must not exceed 32 characters.

 * @param array|string $object_type Object type or array of object types with which the taxonomy should be associated.

 * @param array|string $args        {

 *     Optional. Array or query string of arguments for registering a taxonomy.

 *

 *     @type array         $labels                An array of labels for this taxonomy. By default, Tag labels are

 *                                                used for non-hierarchical taxonomies, and Category labels are used

 *                                                for hierarchical taxonomies. See accepted values in

 *                                                get_taxonomy_labels(). Default empty array.

 *     @type string        $description           A short descriptive summary of what the taxonomy is for. Default empty.

 *     @type bool          $public                Whether a taxonomy is intended for use publicly either via

 *                                                the admin interface or by front-end users. The default settings

 *                                                of `$publicly_queryable`, `$show_ui`, and `$show_in_nav_menus`

 *                                                are inherited from `$public`.

 *     @type bool          $publicly_queryable    Whether the taxonomy is publicly queryable.

 *                                                If not set, the default is inherited from `$public`

 *     @type bool          $hierarchical          Whether the taxonomy is hierarchical. Default false.

 *     @type bool          $show_ui               Whether to generate and allow a UI for managing terms in this taxonomy in

 *                                                the admin. If not set, the default is inherited from `$public`

 *                                                (default true).

 *     @type bool          $show_in_menu          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.

 *                                                `$show_ui` must be true. If not set, default is inherited from `$show_ui`

 *                                                (default true).

 *     @type bool          $show_in_nav_menus     Makes this taxonomy available for selection in navigation menus. If not

 *                                                set, the default is inherited from `$public` (default true).

 *     @type bool          $show_in_rest          Whether to include the taxonomy in the REST API.

 *     @type string        $rest_base             To change the base url of REST API route. Default is $taxonomy.

 *     @type string        $rest_controller_class REST API Controller class name. Default is 'WP_REST_Terms_Controller'.

 *     @type bool          $show_tagcloud         Whether to list the taxonomy in the Tag Cloud Widget controls. If not set,

 *                                                the default is inherited from `$show_ui` (default true).

 *     @type bool          $show_in_quick_edit    Whether to show the taxonomy in the quick/bulk edit panel. It not set,

 *                                                the default is inherited from `$show_ui` (default true).

 *     @type bool          $show_admin_column     Whether to display a column for the taxonomy on its post type listing

 *                                                screens. Default false.

 *     @type bool|callable $meta_box_cb           Provide a callback function for the meta box display. If not set,

 *                                                post_categories_meta_box() is used for hierarchical taxonomies, and

 *                                                post_tags_meta_box() is used for non-hierarchical. If false, no meta

 *                                                box is shown.

 *     @type array         $capabilities {

 *         Array of capabilities for this taxonomy.

 *

 *         @type string $manage_terms Default 'manage_categories'.

 *         @type string $edit_terms   Default 'manage_categories'.

 *         @type string $delete_terms Default 'manage_categories'.

 *         @type string $assign_terms Default 'edit_posts'.

 *     }

 *     @type bool|array    $rewrite {

 *         Triggers the handling of rewrites for this taxonomy. Default true, using $taxonomy as slug. To prevent

 *         rewrite, set to false. To specify rewrite rules, an array can be passed with any of these keys:

 *

 *         @type string $slug         Customize the permastruct slug. Default `$taxonomy` key.

 *         @type bool   $with_front   Should the permastruct be prepended with WP_Rewrite::$front. Default true.

 *         @type bool   $hierarchical Either hierarchical rewrite tag or not. Default false.

 *         @type int    $ep_mask      Assign an endpoint mask. Default `EP_NONE`.

 *     }

 *     @type string        $query_var             Sets the query var key for this taxonomy. Default `$taxonomy` key. If

 *                                                false, a taxonomy cannot be loaded at `?{query_var}={term_slug}`. If a

 *                                                string, the query `?{query_var}={term_slug}` will be valid.

 *     @type callable      $update_count_callback Works much like a hook, in that it will be called when the count is

 *                                                updated. Default _update_post_term_count() for taxonomies attached

 *                                                to post types, which confirms that the objects are published before

 *                                                counting them. Default _update_generic_term_count() for taxonomies

 *                                                attached to other object types, such as users.

 *     @type bool          $_builtin              This taxonomy is a "built-in" taxonomy. INTERNAL USE ONLY!

 *                                                Default false.

 * }

 * @return WP_Error|void WP_Error, if errors.

	global $wp_taxonomies;

	$args = wp_parse_args( $args );

		_doing_it_wrong( __FUNCTION__, __( 'Taxonomy names must be between 1 and 32 characters in length.' ), '4.2.0' );

	$taxonomy_object = new WP_Taxonomy( $taxonomy, $object_type, $args );

	$taxonomy_object->add_rewrite_rules();

	$wp_taxonomies[ $taxonomy ] = $taxonomy_object;

	$taxonomy_object->add_hooks();

	do_action( 'registered_taxonomy', $taxonomy, $object_type, (array) $taxonomy_object );

 * Unregisters a taxonomy.

 *

 * Can not be used to unregister built-in taxonomies.

 *

 * @since 4.5.0

 *

 * @global WP    $wp            Current WordPress environment instance.

 * @global array $wp_taxonomies List of taxonomies.

 *

 * @param string $taxonomy Taxonomy name.

 * @return bool|WP_Error True on success, WP_Error on failure or if the taxonomy doesn't exist.

 */

function unregister_taxonomy( $taxonomy ) {

	if ( ! taxonomy_exists( $taxonomy ) ) {

		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );

	}

	$taxonomy_object = get_taxonomy( $taxonomy );

	// Do not allow unregistering internal taxonomies.

	if ( $taxonomy_object->_builtin ) {

		return new WP_Error( 'invalid_taxonomy', __( 'Unregistering a built-in taxonomy is not allowed.' ) );

	}

	global $wp_taxonomies;

	$taxonomy_object->remove_rewrite_rules();

	$taxonomy_object->remove_hooks();

	// Remove the taxonomy.

	unset( $wp_taxonomies[ $taxonomy ] );

	/**

	 * Fires after a taxonomy is unregistered.

	 *

	 * @since 4.5.0

	 *

	 * @param string $taxonomy Taxonomy name.

	 */

	do_action( 'unregistered_taxonomy', $taxonomy );

	return true;

}

/**

 * Builds an object with all taxonomy labels out of a taxonomy object.

 * @since 4.3.0 Added the `no_terms` label.

 * @since 4.4.0 Added the `items_list_navigation` and `items_list` labels.

 * @since 4.9.0 Added the `most_used` and `back_to_items` labels.

 *

 * @param WP_Taxonomy $tax Taxonomy object.

 * @return object {

 *     Taxonomy labels object. The first default value is for non-hierarchical taxonomies

 *     (like tags) and the second one is for hierarchical taxonomies (like categories).

 *

 *     @type string $name                       General name for the taxonomy, usually plural. The same

 *                                              as and overridden by `$tax->label`. Default 'Tags'/'Categories'.

 *     @type string $singular_name              Name for one object of this taxonomy. Default 'Tag'/'Category'.

 *     @type string $search_items               Default 'Search Tags'/'Search Categories'.

 *     @type string $popular_items              This label is only used for non-hierarchical taxonomies.

 *                                              Default 'Popular Tags'.

 *     @type string $all_items                  Default 'All Tags'/'All Categories'.

 *     @type string $parent_item                This label is only used for hierarchical taxonomies. Default

 *                                              'Parent Category'.

 *     @type string $parent_item_colon          The same as `parent_item`, but with colon `:` in the end.

 *     @type string $edit_item                  Default 'Edit Tag'/'Edit Category'.

 *     @type string $view_item                  Default 'View Tag'/'View Category'.

 *     @type string $update_item                Default 'Update Tag'/'Update Category'.

 *     @type string $add_new_item               Default 'Add New Tag'/'Add New Category'.

 *     @type string $new_item_name              Default 'New Tag Name'/'New Category Name'.

 *     @type string $separate_items_with_commas This label is only used for non-hierarchical taxonomies. Default

 *                                              'Separate tags with commas', used in the meta box.

 *     @type string $add_or_remove_items        This label is only used for non-hierarchical taxonomies. Default

 *                                              'Add or remove tags', used in the meta box when JavaScript

 *                                              is disabled.

 *     @type string $choose_from_most_used      This label is only used on non-hierarchical taxonomies. Default

 *                                              'Choose from the most used tags', used in the meta box.

 *     @type string $not_found                  Default 'No tags found'/'No categories found', used in

 *                                              the meta box and taxonomy list table.

 *     @type string $no_terms                   Default 'No tags'/'No categories', used in the posts and media

 *                                              list tables.

 *     @type string $items_list_navigation      Label for the table pagination hidden heading.

 *     @type string $items_list                 Label for the table hidden heading.

 *     @type string $most_used                  Title for the Most Used tab. Default 'Most Used'.

 *     @type string $back_to_items              Label displayed after a term has been updated.

 * }