CCrmUserType::PrepareForSave

public function PrepareForSave(array &$fields)
{
	$userFields = $this->GetAbstractFields();
	foreach($userFields as $fieldName => $userFieldInfo)
	{
		if($userFieldInfo['USER_TYPE_ID'] === 'file')
		{
			if(isset($userFieldInfo['MULTIPLE']) && $userFieldInfo['MULTIPLE'] === 'Y')
			{
				$results = array();
				if(is_array($fields[$fieldName]))
				{
					foreach($fields[$fieldName] as $data)
					{
						if(\CCrmFileProxy::TryResolveFile($data, $file, array('ENABLE_ID' => true)))
						{
							$results[] = $file;
						}
					}
				}
				$fields[$fieldName] = $results;
			}
			else
			{
				if(\CCrmFileProxy::TryResolveFile($fields[$fieldName], $file, array('ENABLE_ID' => true)))
				{
					$fields[$fieldName] = $file;
				}
			}
		}
	}
}