On 09/10/2012, at 12:10, Alex Zavatone wrote: > 3. If you want to have your GUI respond to changes in the DB, and you have no > method to yap back to the GUI, then seems like you're going to have to poll. > > You might want to consider how to make the basic design work, then plan on > ways that you can see that it will break. You've already outlined a few of > them. Though you hate polling (I mostly agree), you can implement something > better, a heartbeat, where when you initiate part of your GUI, you issue a > request to happen in the future where you check "Am I still using this > thing?" If so, update the time to check again and continue for another. If > you're not, immediately write the change, lock the record and dismiss the > heartbeat. It's polling yeah, but I'm trying to position it differently and > it would only run when you have your edit button clicked.
This heartbeat idea is nice. I could implement this, but still also implement Keary's idea (user trying to edit a locked row will get a message saying who is currently editing it). So, if the client hangs, disconnects (kind of wrong term, because it's HTTP) or loses power, after a certain number of missed heartbeats, changes are discarded and the row is unlocked. If the user tries to edit a locked row, he/she gets notified that "<username> is editing this record now". He can then wait, call <username>'s extension, send a message, or simply throw something at him/her! :) After negotiating with the user that's editing the row, all that is needed is to refresh the view. This way, I wouldn't even require early feedback about a record being locked or not. I think we can call this case closed (it's also gone a little off topic). Thanks again for all the ideas! Cheers, Flavio _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
