3 ms·
"Undo" only makes good sense in an app where each user works in her own isolated sandbox. This is a common paradigm on the desktop (e.g. word processing), but l
by brianberns 13y ago
"Undo" only makes good sense in an app where each user works in her own isolated sandbox. This is a common paradigm on the desktop (e.g. word processing), but less common on the web. As soon as Alice's transaction is visible to Bob, making it undo-able gets much more complex.
- uniclaude 13y agoThis is a good point, but as the author points it, it feels so useful in Gmail.
- Legion 13y agoGmail undo is basically job cancellation, not really returning a changed state back to its original state. Gmail can't "undo" once that job has been processed - in other words, when something has been actually done.
- r00fus 13y agoIt's not job cancellation, your view is such that unless you undo, that's reality (you can confirm this by browsing in a separate window, your non-undone actions have taken place). What Google is doing is (at least for deletes on mails) is equivalent to a database transaction rollback. So they have a tiny (likely 1-entry) transaction log that they keep per user, and if the user desires, they can use it to fully reverse any operation that is undoable aka reversible. I suppose it works different for email sends you can undo - in that case it is job cancellation.
- uniclaude 13y agoWe, on HN, all have an idea of the tech behind this, but to the user, it is still perceived as an undo action, and that's what I believe the point of the author was.
- sesqu 13y agoGmail can't, but Exchange and Skype can (and do).
- jfoster 13y agoHow does Google Drive handle this?
- r00fus 13y agoDoesn't Drive, just like Dropbox, simply version everything similar to a source control system? Using the optimistic locking pattern, this would mean that Alice could undo, and if Bob then makes changes referring to Alice's entry, it'd be pointing to a previous versioned entry (Alice's undo would simply copy version n-2 and make it version n while Bob would be pointing or editing version n-1)
- jfoster 13y agoNot sure. That behaviour would be a little weird, if Alice hitting Ctrl-Z undoes what Bob just did. Google Drive's document editors explicitly appear to support "undo".