That sounds feasable, but depending on how your web application is used you might also have to consider the possibility of multiple web users accessing the same record. You might need some unique user id key included in the token that gets carried around by the web session. I think you would have to completely deny access to all but the first web user because you only have stale data to give them at that point. And of course there's always the possibility someone's browser might crash and cause them to lock themselves out of the application for the pre-determined READU period.
-John -----Original Message----- From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of George Gallen Sent: Wednesday, July 13, 2011 10:28 AM To: U2 Users List Subject: Re: [U2] Record Locks - How long should they last for? (Opinion) > -----Original Message----- > From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users- > boun...@listserver.u2ug.org] On Behalf Of Rex Gozar > Sent: Wednesday, July 13, 2011 1:08 PM > To: U2 Users List > Subject: Re: [U2] Record Locks - How long should they last for? > (Opinion) > > Why not switch to an optimistic locking approach? Checksum the > original data (record) when it is passed to the browser. When > returned from the browser, lock the record and checksum it again. If > the checksums match proceed with the write; otherwise, send a message > back to the browser allowing the user to cancel or resubmit their > changes. This way, record locks should only last a few milliseconds. > I was thinking along similar lines as well as an option, instead of the checksum token method, I was going to write the record to a holding file with an ID that was a combination of file/record/transaction token And do a comparison using the saved item to see if record changed, but only if the record lock had expired - I still wanted to keep the locks since the system could be used by local users as well, which is easier using the READU locally to test for locking. > rex > _______________________________________________ _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users