CCrmInvoiceRestService::tryExternalizeFileField

static function tryExternalizeFileField(&$fields, $fieldName, $multiple = false, $dynamic = true)
{
	if(!isset($fields[$fieldName]))
	{
		return false;
	}

	$ownerTypeID = CCrmOwnerType::Invoice;
	$ownerID = isset($fields['ID']) ? intval($fields['ID']) : 0;
	if(!$multiple)
	{
		$fileID = intval($fields[$fieldName]);
		if($fileID <= 0)
		{
			unset($fields[$fieldName]);
			return false;
		}

		$fields[$fieldName] = self::externalizeFile($ownerTypeID, $ownerID, $fieldName, $fileID, $dynamic);
	}
	else
	{
		$result = array();
		$filesID = $fields[$fieldName];
		if(!is_array($filesID))
		{
			$filesID = array($filesID);
		}

		foreach($filesID as $fileID)
		{
			$fileID = intval($fileID);
			if($fileID > 0)
			{
				$result[] = self::externalizeFile($ownerTypeID, $ownerID, $fieldName, $fileID, $dynamic);
			}
		}
		$fields[$fieldName] = &$result;
		unset($result);
	}

	return true;
}