def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def handleevent(self):
        """
        Event-handler for the 'widgets' demo
        """
        while True:
            event = self.dialog.waitForEvent()
            if event.eventType() == yui.YEvent.CancelEvent:
                self.dialog.destroy()
                break
            if event.widget() == self.closebutton:
                info = Info("Quit confirmation", 1, "Are you sure you want to quit?")
                if self.ask_YesOrNo(info):
                    self.dialog.destroy()
                    break
            if event.widget() == self.aboutbutton:
                self.aboutDialog()