@Override
public Object getValue(Query qr, int row, Object defaultValue) {
if (col == null) {
col = qr.getColumn(getColumn(), null);
if (col == null) return defaultValue;
}
return col.get(row, defaultValue);
}
// MUST hanle null correctly
@Override
public Object getValue(Query qr, int row) throws PageException {
if (col == null) col = qr.getColumn(getColumn());
return QueryUtil.getValue(col, row);
}