protected function renderModelField(string $p_field)
    {
        $parts = explode('.', $p_field);
        $class = $parts[0];
        $field = $parts[1];
        if (!array_key_exists($class, self::$models)) {
            self::$models[$class] = \FreeFW\DI\DI::get($class);
        }
        $model      = self::$models[$class];
        $source     = $model::getSource();
        $properties = $model::getProperties();
        $type       = \FreeFW\Constants::TYPE_STRING;
        if (array_key_exists($field, $properties)) {
            $real = $source . '.' . $properties[$field][FFCST::PROPERTY_PRIVATE];
            $type = $properties[$field][FFCST::PROPERTY_TYPE];
        } else {
            throw new \FreeFW\Core\FreeFWStorageException(
                sprintf('Unknown field : %s !', $p_field)
            );
        }
        return [
            'id'    => $real,
            'value' => $p_field,
            'type'  => $type
        ];
    }