/**
* 增加一个附件
*
* @param PwThreadAttachDm $dm
* @return bool|PwError
*/
public function addAttach(PwThreadAttachDm $dm)
{
if (($result = $dm->beforeAdd()) !== true) {
return $result;
}
if (($result = $this->_getAttach()->addAttach($dm)) instanceof PwError) {
return $result;
}
$dm->setAid($result);
$this->_getDao()->addAttach($dm->getData());
return $result;
}