Method setWhereByOrderStatus

/*
 * changes the $whereStatus variable
 * return true or false, if false, this will influence whole sql query which will be completely ignored
 */
public static function setWhereByOrderStatus(&$whereStatus)
{
    $paramsC = PhocacartUtils::getComponentParameters();
    $statistics_order_status = $paramsC->get('statistics_order_status', array(-1));
    if (in_array(-1, $statistics_order_status)) {
        // All order statuses are set in statistics, where clause not needed
        return true;
    } else {
        if (in_array(0, $statistics_order_status)) {
            // No status selected, no statistics, where clause not needed
            return false;
        } else {
            // Only some statuses selected, so where clause changed
            $whereStatus = 'a.status_id IN (' . implode(',', $statistics_order_status) . ')';
            return true;
        }
    }
    return false;
}