def search(self, regex):
        try:
            spec = {'$or': [{'data.content'    : {'$regex': regex, '$options': 'im'}},
                            {'data.description': {'$regex': regex, '$options': 'im'}}]}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def on_upper_bound_checked_changed(self):
        if self.ui.checkBoxUpperBound.isChecked():
            self.ui.spinBoxUpperBound.setEnabled(True)
            self.ui.spinBoxBoundaryNumber.setEnabled(True)
        elif not self.ui.checkBoxLowerBound.isChecked():
            self.ui.spinBoxUpperBound.setEnabled(False)
            self.ui.spinBoxBoundaryNumber.setEnabled(False)
        else:
            self.ui.spinBoxUpperBound.setEnabled(False)