rest_filter_response_fields( WP_REST_Response $response, WP_REST_Server $server, WP_REST_Request $request )

Filter the API response to include only a white-listed set of response object fields.


Parameters

$response

(WP_REST_Response) (Required) Current response being served.

$server

(WP_REST_Server) (Required) ResponseHandler instance (usually WP_REST_Server).

$request

(WP_REST_Request) (Required) The request that was used to make current response.


Return

(WP_REST_Response) Response to be served, trimmed down to contain a subset of fields.


Source

File: wp-includes/rest-api.php

function rest_filter_response_fields( $response, $server, $request ) {
	if ( ! isset( $request['_fields'] ) || $response->is_error() ) {
		return $response;
	}

	$data = $response->get_data();

	$fields = is_array( $request['_fields']  ) ? $request['_fields'] : preg_split( '/[\s,]+/', $request['_fields'] );

	if ( 0 === count( $fields ) ) {
		return $response;
	}

	// Trim off outside whitespace from the comma delimited list.
	$fields = array_map( 'trim', $fields );

	$fields_as_keyed = array_combine( $fields, array_fill( 0, count( $fields ), true ) );

	if ( wp_is_numeric_array( $data ) ) {
		$new_data = array();
		foreach ( $data as $item ) {
			$new_data[] = array_intersect_key( $item, $fields_as_keyed );
		}
	} else {
		$new_data = array_intersect_key( $data, $fields_as_keyed );
	}

	$response->set_data( $new_data );

	return $response;
}


Changelog

Changelog
Version Description
WP-4.8.0 Introduced.