FieldSynchronizer::getUserFieldBySystemField

protected function getUserFieldBySystemField($dstEntityTypeName, $srcEntityTypeName, $srcFieldName)
{
	$dstEntityTypeId = \CCrmOwnerType::ResolveID($dstEntityTypeName);
	$entityId = \CCrmOwnerType::ResolveUserFieldEntityID($dstEntityTypeId);
	$userTypeEntity = new \CUserTypeEntity();

	$xmlId = $this->getXmlIdUserFieldBySystemField($srcEntityTypeName, $srcFieldName);

	$resultDb = $userTypeEntity->GetList(
		array(),
		array('ENTITY_ID' => $entityId, 'XML_ID' => $xmlId)
	);
	if($dstField = $resultDb->Fetch())
	{
		return $dstField['FIELD_NAME'];
	}

	return null;
}