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filter is not described

rest_request_before_callbacks filter-hook . WP 4.7.0

Filters the response before executing any REST API callbacks.

Allows plugins to perform additional validation after a request is initialized and matched to a registered route, but before it is executed.

Note that this filter will not be called for requests that fail to authenticate or match to a registered route.

Usage

add_filter( 'rest_request_before_callbacks', 'filter_function_name_97', 10, 3 );
function filter_function_name_97( $response, $handler, $request ){
	// filter...

	return $response;
}
$response(WP_HTTP_Response)
Result to send to the client. Usually a WP_REST_Response.
$handler(WP_REST_Server)
ResponseHandler instance (usually WP_REST_Server).
$request(WP_REST_Request)
Request used to generate the response.

Where the hook is called

WP_REST_Server::dispatch()
wp-includes/rest-api/class-wp-rest-server.php 901
$response = apply_filters( 'rest_request_before_callbacks', $response, $handler, $request );

Where the hook is used (in WP core)

Does not used.