VersionUserType::onDelete

static function onDelete($userField, $value)
{
	list($type, $realValue) = self::detectType($value);
	if($type != self::TYPE_ALREADY_ATTACHED)
	{
		return;
	}

	$attachedModel = AttachedObject::loadById($realValue);
	if(!$attachedModel)
	{
		return;
	}

	$userFieldManager = Driver::getInstance()->getUserFieldManager();
	if(!$userFieldManager->belongsToEntity($attachedModel, $userField['ENTITY_ID'], $userField['ENTITY_VALUE_ID']))
	{
		return;
	}

	AttachedObject::detachByFilter(array('ID' => $realValue));
}