RE: [PHP] Locking and unlocking records

One way to do this is to keep a copy of the old record in a session variable. When you com to write the data back read the record again and see if it is still the same. If it is you can save the changes, otherwise give an error saying that the data has been changed, and probably refuse to do the update. You might like to concoct a friendlier failure than this. Olwen Williams olwen.williams@safeair.co.nz -----Original Message----- From: Jason Wong [mailto:php-general@gremlins.biz] Sent: Friday, January 16, 2004 12:05 PM To: php-general@lists.php.net Subject: Re: [PHP] Locking and unlocking records On Friday 16 January 2004 04:49, Lowell Allen wrote: > I need to implement database record locking and unlocking. I want to > prevent multiple users of a content management system from editing the same > record simultaneously, which can result in one user's edits being > overwritten. I can use PHP to lock a record when it's opened, and unlock it > when it's updated or if the user goes anywhere else within the content > management system (or logs out), but I need to account for a user leaving > the CMS directly from the edit screen. I'm not aware of any way to do that > other than using a Javascript onunload event to open a new window, run a > PHP script, and close the new window onload -- very nasty and unreliable > with pop-up blocking so popular. Can anyone suggest an all-PHP way? There is no way to determine whether/when a user 'leaves' the edit screen. The best you can do is to set a timeout on the locked record. So if the person who locked the record hasn't done anything to it for the last 10 minutes (or whatever) then unlock the record. -- ____________________________________________________________________ CAUTION - This message may contain privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message you are hereby notified that any use, dissemination, distribution or reproduction of this message is prohibited. If you have received this message in error please notify Safe Air Ltd immediately. Any views expressed in this message are those of the individual sender and may not necessarily reflect the views of Safe Air. _____________________________________________________________________ For more information on the Safe Air Group, visit us online at http://www.safeair.co.nz/ _____________________________________________________________________