public function addPhpToJs($key, $value)
    {
        if (is_bool($value)) {
            $value = $value ? "true" : "false";
        } elseif (is_string($value)) {
            $value = "\"$value\"";
        } elseif (is_array($value)) {
            $value = json_encode($value);
        } elseif (is_object($value) && method_exists($value, "toArray")) {
            $value = json_encode($value->toArray());
        } else {
            throw new \Exception("Can not translate a parameter from PHP to JS\n".print_r($value, true));
        }

        $this->_themeExtras['phpToJs'][$key] = $value;
    }