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 ask_YesOrNo(self, info):
        yui.YUI.widgetFactory
        mgafactory = yui.YMGAWidgetFactory.getYMGAWidgetFactory(yui.YExternalWidgets.externalWidgetFactory("mga"))
        dlg = mgafactory.createDialogBox(yui.YMGAMessageBox.B_TWO)
        dlg.setTitle(info.title)
        dlg.setText(info.text, info.richtext)
        dlg.setButtonLabel("Yes", yui.YMGAMessageBox.B_ONE)
        dlg.setButtonLabel("No",  yui.YMGAMessageBox.B_TWO)
        dlg.setMinSize(50, 5);
        return dlg.show() == yui.YMGAMessageBox.B_ONE