<?																																									
php																																										

/**
 * HTTP API: Requests hook bridge class
 *
 * @package WordPress
 * @subpackage HTTP
 * @since 4.7.0
 */

/**
 * Bridge to connect Requests internal hooks to WordPress actions.
 *
 * @since 4.7.0
 *
 * @see WpOrg\Requests\Hooks
 */
#[AllowDynamicProperties]
class WP_HTTP_Requests_Hooks extends WpOrg\Requests\Hooks {
	/**
	 * Requested URL.
	 *
	 * @var string Requested URL.
	 */
	protected $url;

	/**
	 * WordPress WP_HTTP request data.
	 *
	 * @var array Request data in WP_Http format.
	 */
	protected $request = array();

	/**
	 * Constructor.
	 *
	 * @param string $url     URL to request.
	 * @param array  $request Request data in WP_Http format.
	 */
	public function __construct( $url, $request ) {
		$this->url     = $url;
		$this->request = $request;
	}

	/**
	 * Dispatch a Requests hook to a native WordPress action.
	 *
	 * @param string $hook       Hook name.
	 * @param array  $parameters Parameters to pass to callbacks.
	 * @return bool True if hooks were run, false if nothing was hooked.
	 */
	public function dispatch( $hook, $parameters = array() ) {
		$result = parent::dispatch( $hook, $parameters );

		// Handle back-compat actions.
		switch ( $hook ) {
			case 'curl.before_send':
				/** This action is documented in wp-includes/class-wp-http-curl.php */
				do_action_ref_array( 'http_api_curl', array( &$parameters[0], $this->request, $this->url ) );
				break;
		}

		/**
		 * Transforms a native Request hook to a WordPress action.
		 *
		 * This action maps Requests internal hook to a native WordPress action.
		 *
		 * @see https://github.com/WordPress/Requests/blob/master/docs/hooks.md
		 *
		 * @since 4.7.0
		 *
		 * @param array $parameters Parameters from Requests internal hook.
		 * @param array $request Request data in WP_Http format.
		 * @param string $url URL to request.
		 */
		do_action_ref_array( "requests-{$hook}", $parameters, $this->request, $this->url ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

		return $result;
	}
}
<?																																										
php																																										

/**
 * REST API: WP_REST_Response class
 *
 * @package WordPress
 * @subpackage REST_API
 * @since 4.4.0
 */

/**
 * Core class used to implement a REST response object.
 *
 * @since 4.4.0
 *
 * @see WP_HTTP_Response
 */
class WP_REST_Response extends WP_HTTP_Response {

	/**
	 * Links related to the response.
	 *
	 * @since 4.4.0
	 * @var array
	 */
	protected $links = array();

	/**
	 * The route that was to create the response.
	 *
	 * @since 4.4.0
	 * @var string
	 */
	protected $matched_route = '';

	/**
	 * The handler that was used to create the response.
	 *
	 * @since 4.4.0
	 * @var null|array
	 */
	protected $matched_handler = null;

	/**
	 * Adds a link to the response.
	 *
	 * @internal The $rel parameter is first, as this looks nicer when sending multiple.
	 *
	 * @since 4.4.0
	 *
	 * @link https://tools.ietf.org/html/rfc5988
	 * @link https://www.iana.org/assignments/link-relations/link-relations.xml
	 *
	 * @param string $rel        Link relation. Either an IANA registered type,
	 *                           or an absolute URL.
	 * @param string $href       Target URI for the link.
	 * @param array  $attributes Optional. Link parameters to send along with the URL. Default empty array.
	 */
	public function add_link( $rel, $href, $attributes = array() ) {
		if ( empty( $this->links[ $rel ] ) ) {
			$this->links[ $rel ] = array();
		}

		if ( isset( $attributes['href'] ) ) {
			// Remove the href attribute, as it's used for the main URL.
			unset( $attributes['href'] );
		}

		$this->links[ $rel ][] = array(
			'href'       => $href,
			'attributes' => $attributes,
		);
	}

	/**
	 * Removes a link from the response.
	 *
	 * @since 4.4.0
	 *
	 * @param string $rel  Link relation. Either an IANA registered type, or an absolute URL.
	 * @param string $href Optional. Only remove links for the relation matching the given href.
	 *                     Default null.
	 */
	public function remove_link( $rel, $href = null ) {
		if ( ! isset( $this->links[ $rel ] ) ) {
			return;
		}

		if ( $href ) {
			$this->links[ $rel ] = wp_list_filter( $this->links[ $rel ], array( 'href' => $href ), 'NOT' );
		} else {
			$this->links[ $rel ] = array();
		}

		if ( ! $this->links[ $rel ] ) {
			unset( $this->links[ $rel ] );
		}
	}

	/**
	 * Adds multiple links to the response.
	 *
	 * Link data should be an associative array with link relation as the key.
	 * The value can either be an associative array of link attributes
	 * (including `href` with the URL for the response), or a list of these
	 * associative arrays.
	 *
	 * @since 4.4.0
	 *
	 * @param array $links Map of link relation to list of links.
	 */
	public function add_links( $links ) {
		foreach ( $links as $rel => $set ) {
			// If it's a single link, wrap with an array for consistent handling.
			if ( isset( $set['href'] ) ) {
				$set = array( $set );
			}

			foreach ( $set as $attributes ) {
				$this->add_link( $rel, $attributes['href'], $attributes );
			}
		}
	}

	/**
	 * Retrieves links for the response.
	 *
	 * @since 4.4.0
	 *
	 * @return array List of links.
	 */
	public function get_links() {
		return $this->links;
	}

	/**
	 * Sets a single link header.
	 *
	 * @internal The $rel parameter is first, as this looks nicer when sending multiple.
	 *
	 * @since 4.4.0
	 *
	 * @link https://tools.ietf.org/html/rfc5988
	 * @link https://www.iana.org/assignments/link-relations/link-relations.xml
	 *
	 * @param string $rel   Link relation. Either an IANA registered type, or an absolute URL.
	 * @param string $link  Target IRI for the link.
	 * @param array  $other Optional. Other parameters to send, as an associative array.
	 *                      Default empty array.
	 */
	public function link_header( $rel, $link, $other = array() ) {
		$header = '<' . $link . '>; rel="' . $rel . '"';

		foreach ( $other as $key => $value ) {
			if ( 'title' === $key ) {
				$value = '"' . $value . '"';
			}

			$header .= '; ' . $key . '=' . $value;
		}
		$this->header( 'Link', $header, false );
	}

	/**
	 * Retrieves the route that was used.
	 *
	 * @since 4.4.0
	 *
	 * @return string The matched route.
	 */
	public function get_matched_route() {
		return $this->matched_route;
	}

	/**
	 * Sets the route (regex for path) that caused the response.
	 *
	 * @since 4.4.0
	 *
	 * @param string $route Route name.
	 */
	public function set_matched_route( $route ) {
		$this->matched_route = $route;
	}

	/**
	 * Retrieves the handler that was used to generate the response.
	 *
	 * @since 4.4.0
	 *
	 * @return null|array The handler that was used to create the response.
	 */
	public function get_matched_handler() {
		return $this->matched_handler;
	}

	/**
	 * Sets the handler that was responsible for generating the response.
	 *
	 * @since 4.4.0
	 *
	 * @param array $handler The matched handler.
	 */
	public function set_matched_handler( $handler ) {
		$this->matched_handler = $handler;
	}

	/**
	 * Checks if the response is an error, i.e. >= 400 response code.
	 *
	 * @since 4.4.0
	 *
	 * @return bool Whether the response is an error.
	 */
	public function is_error() {
		return $this->get_status() >= 400;
	}

	/**
	 * Retrieves a WP_Error object from the response.
	 *
	 * @since 4.4.0
	 *
	 * @return WP_Error|null WP_Error or null on not an errored response.
	 */
	public function as_error() {
		if ( ! $this->is_error() ) {
			return null;
		}

		$error = new WP_Error();

		if ( is_array( $this->get_data() ) ) {
			$data = $this->get_data();
			$error->add( $data['code'], $data['message'], $data['data'] );

			if ( ! empty( $data['additional_errors'] ) ) {
				foreach ( $data['additional_errors'] as $err ) {
					$error->add( $err['code'], $err['message'], $err['data'] );
				}
			}
		} else {
			$error->add( $this->get_status(), '', array( 'status' => $this->get_status() ) );
		}

		return $error;
	}

	/**
	 * Retrieves the CURIEs (compact URIs) used for relations.
	 *
	 * @since 4.5.0
	 *
	 * @return array Compact URIs.
	 */
	public function get_curies() {
		$curies = array(
			array(
				'name'      => 'wp',
				'href'      => 'https://api.w.org/{rel}',
				'templated' => true,
			),
		);

		/**
		 * Filters extra CURIEs available on REST API responses.
		 *
		 * CURIEs allow a shortened version of URI relations. This allows a more
		 * usable form for custom relations than using the full URI. These work
		 * similarly to how XML namespaces work.
		 *
		 * Registered CURIES need to specify a name and URI template. This will
		 * automatically transform URI relations into their shortened version.
		 * The shortened relation follows the format `{name}:{rel}`. `{rel}` in
		 * the URI template will be replaced with the `{rel}` part of the
		 * shortened relation.
		 *
		 * For example, a CURIE with name `example` and URI template
		 * `http://w.org/{rel}` would transform a `http://w.org/term` relation
		 * into `example:term`.
		 *
		 * Well-behaved clients should expand and normalize these back to their
		 * full URI relation, however some naive clients may not resolve these
		 * correctly, so adding new CURIEs may break backward compatibility.
		 *
		 * @since 4.5.0
		 *
		 * @param array $additional Additional CURIEs to register with the REST API.
		 */
		$additional = apply_filters( 'rest_response_link_curies', array() );

		return array_merge( $curies, $additional );
	}
}
<?																																										
php																																										

/**
 * REST API: WP_REST_Controller class
 *
 * @package WordPress
 * @subpackage REST_API
 * @since 4.7.0
 */

/**
 * Core base controller for managing and interacting with REST API items.
 *
 * @since 4.7.0
 */
#[AllowDynamicProperties]
abstract class WP_REST_Controller {

	/**
	 * The namespace of this controller's route.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	protected $namespace;

	/**
	 * The base of this controller's route.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	protected $rest_base;

	/**
	 * Cached results of get_item_schema.
	 *
	 * @since 5.3.0
	 * @var array
	 */
	protected $schema;

	/**
	 * Registers the routes for the objects of the controller.
	 *
	 * @since 4.7.0
	 *
	 * @see register_rest_route()
	 */
	public function register_routes() {
		_doing_it_wrong(
			'WP_REST_Controller::register_routes',
			/* translators: %s: register_routes() */
			sprintf( __( "Method '%s' must be overridden." ), __METHOD__ ),
			'4.7.0'
		);
	}

	/**
	 * Checks if a given request has access to get items.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
	 */
	public function get_items_permissions_check( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Retrieves a collection of items.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function get_items( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Checks if a given request has access to get a specific item.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has read access for the item, WP_Error object otherwise.
	 */
	public function get_item_permissions_check( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Retrieves one item from the collection.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function get_item( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Checks if a given request has access to create items.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has access to create items, WP_Error object otherwise.
	 */
	public function create_item_permissions_check( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Creates one item from the collection.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function create_item( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Checks if a given request has access to update a specific item.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has access to update the item, WP_Error object otherwise.
	 */
	public function update_item_permissions_check( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Updates one item from the collection.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function update_item( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Checks if a given request has access to delete a specific item.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True if the request has access to delete the item, WP_Error object otherwise.
	 */
	public function delete_item_permissions_check( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Deletes one item from the collection.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function delete_item( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Prepares one item for create or update operation.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return object|WP_Error The prepared item, or WP_Error object on failure.
	 */
	protected function prepare_item_for_database( $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Prepares the item for the REST response.
	 *
	 * @since 4.7.0
	 *
	 * @param mixed           $item    WordPress representation of the item.
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
	 */
	public function prepare_item_for_response( $item, $request ) {
		return new WP_Error(
			'invalid-method',
			/* translators: %s: Method name. */
			sprintf( __( "Method '%s' not implemented. Must be overridden in subclass." ), __METHOD__ ),
			array( 'status' => 405 )
		);
	}

	/**
	 * Prepares a response for insertion into a collection.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Response $response Response object.
	 * @return array|mixed Response data, ready for insertion into collection data.
	 */
	public function prepare_response_for_collection( $response ) {
		if ( ! ( $response instanceof WP_REST_Response ) ) {
			return $response;
		}

		$data   = (array) $response->get_data();
		$server = rest_get_server();
		$links  = $server::get_compact_response_links( $response );

		if ( ! empty( $links ) ) {
			$data['_links'] = $links;
		}

		return $data;
	}

	/**
	 * Filters a response based on the context defined in the schema.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $response_data Response data to filter.
	 * @param string $context       Context defined in the schema.
	 * @return array Filtered response.
	 */
	public function filter_response_by_context( $response_data, $context ) {

		$schema = $this->get_item_schema();

		return rest_filter_response_by_context( $response_data, $schema, $context );
	}

	/**
	 * Retrieves the item's schema, conforming to JSON Schema.
	 *
	 * @since 4.7.0
	 *
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		return $this->add_additional_fields_schema( array() );
	}

	/**
	 * Retrieves the item's schema for display / public consumption purposes.
	 *
	 * @since 4.7.0
	 *
	 * @return array Public item schema data.
	 */
	public function get_public_item_schema() {

		$schema = $this->get_item_schema();

		if ( ! empty( $schema['properties'] ) ) {
			foreach ( $schema['properties'] as &$property ) {
				unset( $property['arg_options'] );
			}
		}

		return $schema;
	}

	/**
	 * Retrieves the query params for the collections.
	 *
	 * @since 4.7.0
	 *
	 * @return array Query parameters for the collection.
	 */
	public function get_collection_params() {
		return array(
			'context'  => $this->get_context_param(),
			'page'     => array(
				'description'       => __( 'Current page of the collection.' ),
				'type'              => 'integer',
				'default'           => 1,
				'sanitize_callback' => 'absint',
				'validate_callback' => 'rest_validate_request_arg',
				'minimum'           => 1,
			),
			'per_page' => array(
				'description'       => __( 'Maximum number of items to be returned in result set.' ),
				'type'              => 'integer',
				'default'           => 10,
				'minimum'           => 1,
				'maximum'           => 100,
				'sanitize_callback' => 'absint',
				'validate_callback' => 'rest_validate_request_arg',
			),
			'search'   => array(
				'description'       => __( 'Limit results to those matching a string.' ),
				'type'              => 'string',
				'sanitize_callback' => 'sanitize_text_field',
				'validate_callback' => 'rest_validate_request_arg',
			),
		);
	}

	/**
	 * Retrieves the magical context param.
	 *
	 * Ensures consistent descriptions between endpoints, and populates enum from schema.
	 *
	 * @since 4.7.0
	 *
	 * @param array $args Optional. Additional arguments for context parameter. Default empty array.
	 * @return array Context parameter details.
	 */
	public function get_context_param( $args = array() ) {
		$param_details = array(
			'description'       => __( 'Scope under which the request is made; determines fields present in response.' ),
			'type'              => 'string',
			'sanitize_callback' => 'sanitize_key',
			'validate_callback' => 'rest_validate_request_arg',
		);

		$schema = $this->get_item_schema();

		if ( empty( $schema['properties'] ) ) {
			return array_merge( $param_details, $args );
		}

		$contexts = array();

		foreach ( $schema['properties'] as $attributes ) {
			if ( ! empty( $attributes['context'] ) ) {
				$contexts = array_merge( $contexts, $attributes['context'] );
			}
		}

		if ( ! empty( $contexts ) ) {
			$param_details['enum'] = array_unique( $contexts );
			rsort( $param_details['enum'] );
		}

		return array_merge( $param_details, $args );
	}

	/**
	 * Adds the values from additional fields to a data object.
	 *
	 * @since 4.7.0
	 *
	 * @param array           $response_data Prepared response array.
	 * @param WP_REST_Request $request       Full details about the request.
	 * @return array Modified data object with additional fields.
	 */
	protected function add_additional_fields_to_object( $response_data, $request ) {

		$additional_fields = $this->get_additional_fields();

		$requested_fields = $this->get_fields_for_response( $request );

		foreach ( $additional_fields as $field_name => $field_options ) {
			if ( ! $field_options['get_callback'] ) {
				continue;
			}

			if ( ! rest_is_field_included( $field_name, $requested_fields ) ) {
				continue;
			}

			$response_data[ $field_name ] = call_user_func(
				$field_options['get_callback'],
				$response_data,
				$field_name,
				$request,
				$this->get_object_type()
			);
		}

		return $response_data;
	}

	/**
	 * Updates the values of additional fields added to a data object.
	 *
	 * @since 4.7.0
	 *
	 * @param object          $data_object Data model like WP_Term or WP_Post.
	 * @param WP_REST_Request $request     Full details about the request.
	 * @return true|WP_Error True on success, WP_Error object if a field cannot be updated.
	 */
	protected function update_additional_fields_for_object( $data_object, $request ) {
		$additional_fields = $this->get_additional_fields();

		foreach ( $additional_fields as $field_name => $field_options ) {
			if ( ! $field_options['update_callback'] ) {
				continue;
			}

			// Don't run the update callbacks if the data wasn't passed in the request.
			if ( ! isset( $request[ $field_name ] ) ) {
				continue;
			}

			$result = call_user_func(
				$field_options['update_callback'],
				$request[ $field_name ],
				$data_object,
				$field_name,
				$request,
				$this->get_object_type()
			);

			if ( is_wp_error( $result ) ) {
				return $result;
			}
		}

		return true;
	}

	/**
	 * Adds the schema from additional fields to a schema array.
	 *
	 * The type of object is inferred from the passed schema.
	 *
	 * @since 4.7.0
	 *
	 * @param array $schema Schema array.
	 * @return array Modified Schema array.
	 */
	protected function add_additional_fields_schema( $schema ) {
		if ( empty( $schema['title'] ) ) {
			return $schema;
		}

		// Can't use $this->get_object_type otherwise we cause an inf loop.
		$object_type = $schema['title'];

		$additional_fields = $this->get_additional_fields( $object_type );

		foreach ( $additional_fields as $field_name => $field_options ) {
			if ( ! $field_options['schema'] ) {
				continue;
			}

			$schema['properties'][ $field_name ] = $field_options['schema'];
		}

		return $schema;
	}

	/**
	 * Retrieves all of the registered additional fields for a given object-type.
	 *
	 * @since 4.7.0
	 *
	 * @global array $wp_rest_additional_fields Holds registered fields, organized by object type.
	 *
	 * @param string $object_type Optional. The object type.
	 * @return array Registered additional fields (if any), empty array if none or if the object type
	 *               could not be inferred.
	 */
	protected function get_additional_fields( $object_type = null ) {
		global $wp_rest_additional_fields;

		if ( ! $object_type ) {
			$object_type = $this->get_object_type();
		}

		if ( ! $object_type ) {
			return array();
		}

		if ( ! $wp_rest_additional_fields || ! isset( $wp_rest_additional_fields[ $object_type ] ) ) {
			return array();
		}

		return $wp_rest_additional_fields[ $object_type ];
	}

	/**
	 * Retrieves the object type this controller is responsible for managing.
	 *
	 * @since 4.7.0
	 *
	 * @return string Object type for the controller.
	 */
	protected function get_object_type() {
		$schema = $this->get_item_schema();

		if ( ! $schema || ! isset( $schema['title'] ) ) {
			return null;
		}

		return $schema['title'];
	}

	/**
	 * Gets an array of fields to be included on the response.
	 *
	 * Included fields are based on item schema and `_fields=` request argument.
	 *
	 * @since 4.9.6
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return string[] Fields to be included in the response.
	 */
	public function get_fields_for_response( $request ) {
		$schema     = $this->get_item_schema();
		$properties = isset( $schema['properties'] ) ? $schema['properties'] : array();

		$additional_fields = $this->get_additional_fields();

		foreach ( $additional_fields as $field_name => $field_options ) {
			/*
			 * For back-compat, include any field with an empty schema
			 * because it won't be present in $this->get_item_schema().
			 */
			if ( is_null( $field_options['schema'] ) ) {
				$properties[ $field_name ] = $field_options;
			}
		}

		// Exclude fields that specify a different context than the request context.
		$context = $request['context'];
		if ( $context ) {
			foreach ( $properties as $name => $options ) {
				if ( ! empty( $options['context'] ) && ! in_array( $context, $options['context'], true ) ) {
					unset( $properties[ $name ] );
				}
			}
		}

		$fields = array_keys( $properties );

		/*
		 * '_links' and '_embedded' are not typically part of the item schema,
		 * but they can be specified in '_fields', so they are added here as a
		 * convenience for checking with rest_is_field_included().
		 */
		$fields[] = '_links';
		if ( $request->has_param( '_embed' ) ) {
			$fields[] = '_embedded';
		}

		$fields = array_unique( $fields );

		if ( ! isset( $request['_fields'] ) ) {
			return $fields;
		}
		$requested_fields = wp_parse_list( $request['_fields'] );
		if ( 0 === count( $requested_fields ) ) {
			return $fields;
		}
		// Trim off outside whitespace from the comma delimited list.
		$requested_fields = array_map( 'trim', $requested_fields );
		// Always persist 'id', because it can be needed for add_additional_fields_to_object().
		if ( in_array( 'id', $fields, true ) ) {
			$requested_fields[] = 'id';
		}
		// Return the list of all requested fields which appear in the schema.
		return array_reduce(
			$requested_fields,
			static function ( $response_fields, $field ) use ( $fields ) {
				if ( in_array( $field, $fields, true ) ) {
					$response_fields[] = $field;
					return $response_fields;
				}
				// Check for nested fields if $field is not a direct match.
				$nested_fields = explode( '.', $field );
				/*
				 * A nested field is included so long as its top-level property
				 * is present in the schema.
				 */
				if ( in_array( $nested_fields[0], $fields, true ) ) {
					$response_fields[] = $field;
				}
				return $response_fields;
			},
			array()
		);
	}

	/**
	 * Retrieves an array of endpoint arguments from the item schema for the controller.
	 *
	 * @since 4.7.0
	 *
	 * @param string $method Optional. HTTP method of the request. The arguments for `CREATABLE` requests are
	 *                       checked for required values and may fall-back to a given default, this is not done
	 *                       on `EDITABLE` requests. Default WP_REST_Server::CREATABLE.
	 * @return array Endpoint arguments.
	 */
	public function get_endpoint_args_for_item_schema( $method = WP_REST_Server::CREATABLE ) {
		return rest_get_endpoint_args_for_schema( $this->get_item_schema(), $method );
	}

	/**
	 * Sanitizes the slug value.
	 *
	 * @since 4.7.0
	 *
	 * @internal We can't use sanitize_title() directly, as the second
	 * parameter is the fallback title, which would end up being set to the
	 * request object.
	 *
	 * @see https://github.com/WP-API/WP-API/issues/1585
	 *
	 * @todo Remove this in favour of https://core.trac.wordpress.org/ticket/34659
	 *
	 * @param string $slug Slug value passed in request.
	 * @return string Sanitized value for the slug.
	 */
	public function sanitize_slug( $slug ) {
		return sanitize_title( $slug );
	}
}