public static function get_string_from_input($string) {
        $string = trim($string);

        if (preg_match('|^([a-zA-Z][a-zA-Z0-9\.:/_-]*),([a-zA-Z][a-zA-Z0-9\.:/_-]*)$|', $string, $matches)) {
            if ($matches[2] === 'moodle') {
                $matches[2] = 'core';
            }

            if (get_string_manager()->string_exists($matches[1], $matches[2])) {
                $string = get_string($matches[1], $matches[2]);
            }
        }

        return $string;
    }