eZ\Publish\Core\REST\Server\Output\ValueObjectVisitor\RestRelation::getRelationTypeString PHP Метод

    protected function getRelationTypeString($relationType)
    {
        switch ($relationType) {
            case RelationValue::COMMON:
                return 'COMMON';
            case RelationValue::EMBED:
                return 'EMBED';
            case RelationValue::LINK:
                return 'LINK';
            case RelationValue::FIELD:
                return 'ATTRIBUTE';
        }
        throw new \Exception('Unknown relation type ' . $relationType . '.');
    }