UndoBatch doesn't allow for cancellation of batch

[nathanaw]

The documentation says that UndoBatch is designed similarly to TransactionScope, but TransactionScope requires a "ts.Complete()" call to commit, otherwise the change is rolled back. In the current UndoBatch, there's no ability to rollback. Conforming to the TransactionScope pattern, or at least providing some kind of .Rollback() would be very useful.

---

I worked around it with

bool success = true;
using (new UndoBatch(...)) {
    ...
}

if (!success) {
    var root = UndoService.Current[undoroot];
    root.Undo();
}

[nathanaw]

Thank you for the feedback.

I need to think about this one a bit. For now, I've removed the note in the docs that compares the UndoBatch to TransactionScope.

If we do want to support the "Complete()" type behavior, I think we'll need to add a new "UndoScope" class for that. Changing the UndoBatch's behavior would be a breaking change for those using the library today.