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function is not described

rest_handle_options_request() WP 4.4.0

Handles OPTIONS requests for the server.

This is handled outside of the server code, as it doesn't obey normal route mapping.

No Hooks.

Return

WP_REST_Response. Modified response, either response or null to indicate pass-through.

Usage

rest_handle_options_request( $response, $handler, $request );
$response(mixed) (required)
Current response, either response or null to indicate pass-through.
$handler(WP_REST_Server) (required)
ResponseHandler instance (usually WP_REST_Server).
$request(WP_REST_Request) (required)
The request that was used to make current response.

Changelog

Since 4.4.0 Introduced.

Code of rest handle options request: wp-includes/rest-api.php WP 5.2.2

<?php
function rest_handle_options_request( $response, $handler, $request ) {
	if ( ! empty( $response ) || $request->get_method() !== 'OPTIONS' ) {
		return $response;
	}

	$response = new WP_REST_Response();
	$data     = array();

	foreach ( $handler->get_routes() as $route => $endpoints ) {
		$match = preg_match( '@^' . $route . '$@i', $request->get_route(), $matches );

		if ( ! $match ) {
			continue;
		}

		$args = array();
		foreach ( $matches as $param => $value ) {
			if ( ! is_int( $param ) ) {
				$args[ $param ] = $value;
			}
		}

		foreach ( $endpoints as $endpoint ) {
			// Remove the redundant preg_match argument.
			unset( $args[0] );

			$request->set_url_params( $args );
			$request->set_attributes( $endpoint );
		}

		$data = $handler->get_data_for_route( $route, $endpoints, 'help' );
		$response->set_matched_route( $route );
		break;
	}

	$response->set_data( $data );
	return $response;
}