Kills WordPress execution and displays JSON response with an error message.

This is the handler for wp_die() when processing JSON requests.

function _json_wp_die_handler( $message, $title = '', $args = array() ) {
	list( $message, $title, $parsed_args ) = _wp_die_process_input( $message, $title, $args );

	$data = array(
		'code'              => $parsed_args['code'],
		'message'           => $message,
		'data'              => array(
			'status' => $parsed_args['response'],
		),
		'additional_errors' => $parsed_args['additional_errors'],
	);

	if ( ! headers_sent() ) {
		header( "Content-Type: application/json; charset={$parsed_args['charset']}" );
		if ( null !== $parsed_args['response'] ) {
			status_header( $parsed_args['response'] );
		}
		nocache_headers();
	}

	echo wp_json_encode( $data );
	if ( $parsed_args['exit'] ) {
		die();
	}
}