Github user bitstorm commented on the issue:
https://github.com/apache/wicket/pull/342
@svenmeier sorry, what I said wasn't correct. By calling onDetach we don't
discard the current page instance but we force configuration phase to be
performed again before the actual rendering phase, so no information is lost.
I still think this can be an improvement because users expect onConfigure
to be called before the actual rendering and after event/submission handling.---
