register_theme_feature( string $feature, array $args = array() )

Registers a theme feature for use in add_theme_support().

Description

This does not indicate that the active theme supports the feature, it only describes the feature’s supported options.

Parameters

$feature

(Required) The name uniquely identifying the feature. See add_theme_support() for the list of possible values.

$args

(Optional) Data used to describe the theme.

'type'
(string) The type of data associated with this feature. Valid values are 'string', 'boolean', 'integer', 'number', 'array', and 'object'. Defaults to 'boolean'.
'variadic'
(bool) Does this feature utilize the variadic support of add_theme_support(), or are all arguments specified as the second parameter. Must be used with the "array" type.
'description'
(string) A short description of the feature. Included in the Themes REST API schema. Intended for developers.
'show_in_rest'
(bool|array) Whether this feature should be included in the Themes REST API endpoint. Defaults to not being included. When registering an 'array' or 'object' type, this argument must be an array with the 'schema' key. 
- 'schema'
 (array) Specifies the JSON Schema definition describing the feature. If any objects in the schema do not include the 'additionalProperties' keyword, it is set to false. 
- 'name'
 (string) An alternate name to be used as the property name in the REST API. 
- 'prepare_callback'
 (callable) A function used to format the theme support in the REST API. Receives the raw theme support value.

Default value: array()

Return

(true|WP_Error) True if the theme feature was successfully registered, a WP_Error object if not.

Source

File: wp-includes/theme.php

function register_theme_feature( $feature, $args = array() ) {
	global $_wp_registered_theme_features;

	if ( ! is_array( $_wp_registered_theme_features ) ) {
		$_wp_registered_theme_features = array();
	}

	$defaults = array(
		'type'         => 'boolean',
		'variadic'     => false,
		'description'  => '',
		'show_in_rest' => false,
	);

	$args = wp_parse_args( $args, $defaults );

	if ( true === $args['show_in_rest'] ) {
		$args['show_in_rest'] = array();
	}

	if ( is_array( $args['show_in_rest'] ) ) {
		$args['show_in_rest'] = wp_parse_args(
			$args['show_in_rest'],
			array(
				'schema'           => array(),
				'name'             => $feature,
				'prepare_callback' => null,
			)
		);
	}

	if ( ! in_array( $args['type'], array( 'string', 'boolean', 'integer', 'number', 'array', 'object' ), true ) ) {
		return new WP_Error(
			'invalid_type',
			__( 'The feature "type" is not valid JSON Schema type.' )
		);
	}

	if ( true === $args['variadic'] && 'array' !== $args['type'] ) {
		return new WP_Error(
			'variadic_must_be_array',
			__( 'When registering a "variadic" theme feature, the "type" must be an "array".' )
		);
	}

	if ( false !== $args['show_in_rest'] && in_array( $args['type'], array( 'array', 'object' ), true ) ) {
		if ( ! is_array( $args['show_in_rest'] ) || empty( $args['show_in_rest']['schema'] ) ) {
			return new WP_Error(
				'missing_schema',
				__( 'When registering an "array" or "object" feature to show in the REST API, the feature\'s schema must also be defined.' )
			);
		}

		if ( 'array' === $args['type'] && ! isset( $args['show_in_rest']['schema']['items'] ) ) {
			return new WP_Error(
				'missing_schema_items',
				__( 'When registering an "array" feature, the feature\'s schema must include the "items" keyword.' )
			);
		}

		if ( 'object' === $args['type'] && ! isset( $args['show_in_rest']['schema']['properties'] ) ) {
			return new WP_Error(
				'missing_schema_properties',
				__( 'When registering an "object" feature, the feature\'s schema must include the "properties" keyword.' )
			);
		}
	}

	if ( is_array( $args['show_in_rest'] ) ) {
		if ( isset( $args['show_in_rest']['prepare_callback'] )
			&& ! is_callable( $args['show_in_rest']['prepare_callback'] )
		) {
			return new WP_Error(
				'invalid_rest_prepare_callback',
				sprintf(
					/* translators: %s: prepare_callback */
					__( 'The "%s" must be a callable function.' ),
					'prepare_callback'
				)
			);
		}

		$args['show_in_rest']['schema'] = wp_parse_args(
			$args['show_in_rest']['schema'],
			array(
				'description' => $args['description'],
				'type'        => $args['type'],
				'default'     => false,
			)
		);

		if ( is_bool( $args['show_in_rest']['schema']['default'] )
			&& ! in_array( 'boolean', (array) $args['show_in_rest']['schema']['type'], true )
		) {
			// Automatically include the "boolean" type when the default value is a boolean.
			$args['show_in_rest']['schema']['type'] = (array) $args['show_in_rest']['schema']['type'];
			array_unshift( $args['show_in_rest']['schema']['type'], 'boolean' );
		}

		$args['show_in_rest']['schema'] = rest_default_additional_properties_to_false( $args['show_in_rest']['schema'] );
	}

	$_wp_registered_theme_features[ $feature ] = $args;

	return true;
}

Expand Source Code View on GitHub

Used By

Used By
Used By	Description
wp-includes/theme.php: create_initial_theme_features()	Creates the initial theme features when the ‘setup_theme’ action is fired.

Changelog

Changelog
Version	Description
5.5.0	Introduced.