=> array( 'taxonomy', 'post_type', 'post_type_archive', 'custom' ),
			'context'     => array( 'view', 'edit', 'embed' ),
			'default'     => 'custom',
		);

		$schema['properties']['status'] = array(
			'description' => __( 'A named status for the object.' ),
			'type'        => 'string',
			'enum'        => array_keys( get_post_stati( array( 'internal' => false ) ) ),
			'default'     => 'publish',
			'context'     => array( 'view', 'edit', 'embed' ),
		);

		$schema['properties']['parent'] = array(
			'description' => __( 'The ID for the parent of the object.' ),
			'type'        => 'integer',
			'minimum'     => 0,
			'default'     => 0,
			'context'     => array( 'view', 'edit', 'embed' ),
		);

		$schema['properties']['attr_title'] = array(
			'description' => __( 'Text for the title attribute of the link element for this menu item.' ),
			'type'        => 'string',
			'context'     => array( 'view', 'edit', 'embed' ),
			'arg_options' => array(
				'sanitize_callback' => 'sanitize_text_field',
			),
		);

		$schema['properties']['classes'] = array(
			'description' => __( 'Class names for the link element of this menu item.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'string',
			),
			'context'     => array( 'view', 'edit', 'embed' ),
			'arg_options' => array(
				'sanitize_callback' => static function ( $value ) {
					return array_map( 'sanitize_html_class', wp_parse_list( $value ) );
				},
			),
		);

		$schema['properties']['description'] = array(
			'description' => __( 'The description of this menu item.' ),
			'type'        => 'string',
			'context'     => array( 'view', 'edit', 'embed' ),
			'arg_options' => array(
				'sanitize_callback' => 'sanitize_text_field',
			),
		);

		$schema['properties']['menu_order'] = array(
			'description' => __( 'The DB ID of the nav_menu_item that is this item\'s menu parent, if any, otherwise 0.' ),
			'context'     => array( 'view', 'edit', 'embed' ),
			'type'        => 'integer',
			'minimum'     => 1,
			'default'     => 1,
		);

		$schema['properties']['object'] = array(
			'description' => __( 'The type of object originally represented, such as "category", "post", or "attachment".' ),
			'context'     => array( 'view', 'edit', 'embed' ),
			'type'        => 'string',
			'arg_options' => array(
				'sanitize_callback' => 'sanitize_key',
			),
		);

		$schema['properties']['object_id'] = array(
			'description' => __( 'The database ID of the original object this menu item represents, for example the ID for posts or the term_id for categories.' ),
			'context'     => array( 'view', 'edit', 'embed' ),
			'type'        => 'integer',
			'minimum'     => 0,
			'default'     => 0,
		);

		$schema['properties']['target'] = array(
			'description' => __( 'The target attribute of the link element for this menu item.' ),
			'type'        => 'string',
			'context'     => array( 'view', 'edit', 'embed' ),
			'enum'        => array(
				'_blank',
				'',
			),
		);

		$schema['properties']['url'] = array(
			'description' => __( 'The URL to which this menu item points.' ),
			'type'        => 'string',
			'format'      => 'uri',
			'context'     => array( 'view', 'edit', 'embed' ),
			'arg_options' => array(
				'validate_callback' => static function ( $url ) {
					if ( '' === $url ) {
						return true;
					}

					if ( sanitize_url( $url ) ) {
						return true;
					}

					return new WP_Error(
						'rest_invalid_url',
						__( 'Invalid URL.' )
					);
				},
			),
		);

		$schema['properties']['xfn'] = array(
			'description' => __( 'The XFN relationship expressed in the link of this menu item.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'string',
			),
			'context'     => array( 'view', 'edit', 'embed' ),
			'arg_options' => array(
				'sanitize_callback' => static function ( $value ) {
					return array_map( 'sanitize_html_class', wp_parse_list( $value ) );
				},
			),
		);

		$schema['properties']['invalid'] = array(
			'description' => __( 'Whether the menu item represents an object that no longer exists.' ),
			'context'     => array( 'view', 'edit', 'embed' ),
			'type'        => 'boolean',
			'readonly'    => true,
		);

		$taxonomies = wp_list_filter( get_object_taxonomies( $this->post_type, 'objects' ), array( 'show_in_rest' => true ) );

		foreach ( $taxonomies as $taxonomy ) {
			$base                          = ! empty( $taxonomy->rest_base ) ? $taxonomy->rest_base : $taxonomy->name;
			$schema['properties'][ $base ] = array(
				/* translators: %s: taxonomy name */
				'description' => sprintf( __( 'The terms assigned to the object in the %s taxonomy.' ), $taxonomy->name ),
				'type'        => 'array',
				'items'       => array(
					'type' => 'integer',
				),
				'context'     => array( 'view', 'edit' ),
			);

			if ( 'nav_menu' === $taxonomy->name ) {
				$schema['properties'][ $base ]['type'] = 'integer';
				unset( $schema['properties'][ $base ]['items'] );
			}
		}

		$schema['properties']['meta'] = $this->meta->get_field_schema();

		$schema_links = $this->get_schema_links();

		if ( $schema_links ) {
			$schema['links'] = $schema_links;
		}

		$this->schema = $schema;

		return $this->add_additional_fields_schema( $this->schema );
	}

	/**
	 * Retrieves the query params for the posts collection.
	 *
	 * @since 5.9.0
	 *
	 * @return array Collection parameters.
	 */
	public function get_collection_params() {
		$query_params = parent::get_collection_params();

		$query_params['menu_order'] = array(
			'description' => __( 'Limit result set to posts with a specific menu_order value.' ),
			'type'        => 'integer',
		);

		$query_params['order'] = array(
			'description' => __( 'Order sort attribute ascending or descending.' ),
			'type'        => 'string',
			'default'     => 'asc',
			'enum'        => array( 'asc', 'desc' ),
		);

		$query_params['orderby'] = array(
			'description' => __( 'Sort collection by object attribute.' ),
			'type'        => 'string',
			'default'     => 'menu_order',
			'enum'        => array(
				'author',
				'date',
				'id',
				'include',
				'modified',
				'parent',
				'relevance',
				'slug',
				'include_slugs',
				'title',
				'menu_order',
			),
		);
		// Change default to 100 items.
		$query_params['per_page']['default'] = 100;

		return $query_params;
	}

	/**
	 * Determines the allowed query_vars for a get_items() response and prepares
	 * them for WP_Query.
	 *
	 * @since 5.9.0
	 *
	 * @param array           $prepared_args Optional. Prepared WP_Query arguments. Default empty array.
	 * @param WP_REST_Request $request       Optional. Full details about the request.
	 * @return array Items query arguments.
	 */
	protected function prepare_items_query( $prepared_args = array(), $request = null ) {
		$query_args = parent::prepare_items_query( $prepared_args, $request );

		// Map to proper WP_Query orderby param.
		if ( isset( $query_args['orderby'], $request['orderby'] ) ) {
			$orderby_mappings = array(
				'id'            => 'ID',
				'include'       => 'post__in',
				'slug'          => 'post_name',
				'include_slugs' => 'post_name__in',
				'menu_order'    => 'menu_order',
			);

			if ( isset( $orderby_mappings[ $request['orderby'] ] ) ) {
				$query_args['orderby'] = $orderby_mappings[ $request['orderby'] ];
			}
		}

		$query_args['update_menu_item_cache'] = true;

		return $query_args;
	}

	/**
	 * Gets the id of the menu that the given menu item belongs to.
	 *
	 * @since 5.9.0
	 *
	 * @param int $menu_item_id Menu item id.
	 * @return int
	 */
	protected function get_menu_id( $menu_item_id ) {
		$menu_ids = wp_get_post_terms( $menu_item_id, 'nav_menu', array( 'fields' => 'ids' ) );
		$menu_id  = 0;
		if ( $menu_ids && ! is_wp_error( $menu_ids ) ) {
			$menu_id = array_shift( $menu_ids );
		}

		return $menu_id;
	}
}