Hello all, I want to do the following: commit a change to an object, then commit another. Now I want to undo the second change. Easy: get the tid using undoLog and call undo(tid, transaction.get()). Now the following transactions are in the DB:
- Change 1 - Change 2 - Undo change 2 Now I want to take the DB back to the state before any of the three transactions were commited. I can find no way to do this because all the transactions change the same object and therefor I can never undo more than the most resent one. It seems to me reasonable that with this state ZODB should be able to undo "Change 1" because it is actually in the same state as it was between change 1 and change 2. I tried undoing them all in one transaction in hopes that the system would smart enough to know that it would not cause a conflict, but no luck. The reason for all this is that I want to implement standard GUI-style undo/redo features in a ZODB application. Probably the easiest way to provide this functionality would be to implement a kind of undo that undoes all transactions back to a given point. Also in the back of my mind is the idea of being able to configure a connection to give me a non-current view of the DB (using MVCC). This would allow me to implement suffisticated diff'ing algorithms between states of the DB. This seems like it would be very easy to implement. With MVCC in place and all. And would allow applications to implement much more suffisticates undo than could be implemented in the current system. Thoughts? and is this what custom conflict resolution is for? Thanks. -Arthur _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
