W3cubDocs

/WordPress

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 = wp_parse_list( $request['_fields'] );

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

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

	// Create nested array of accepted field hierarchy.
	$fields_as_keyed = array();
	foreach ( $fields as $field ) {
		$parts = explode( '.', $field );
		$ref   = &$fields_as_keyed;
		while ( count( $parts ) > 1 ) {
			$next = array_shift( $parts );
			if ( isset( $ref[ $next ] ) && true === $ref[ $next ] ) {
				// Skip any sub-properties if their parent prop is already marked for inclusion.
				break 2;
			}
			$ref[ $next ] = isset( $ref[ $next ] ) ? $ref[ $next ] : array();
			$ref          = &$ref[ $next ];
		}
		$last         = array_shift( $parts );
		$ref[ $last ] = true;
	}

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

	$response->set_data( $new_data );

	return $response;
}

Uses

Uses Description
wp-includes/rest-api.php: _rest_array_intersect_key_recursive()

Recursively computes the intersection of arrays using keys for comparison.
wp-includes/functions.php: wp_parse_list()

Cleans up an array, comma- or space-separated list of scalar values.
wp-includes/functions.php: wp_is_numeric_array()

Determines if the variable is a numeric-indexed array.

Changelog

Version Description
4.8.0 Introduced.

© 2003–2019 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/rest_filter_response_fields