Flarum\Core\Search\ApplySearchParametersTrait::applySort PHP Method

    protected function applySort(AbstractSearch $search, array $sort = null)
    {
        $sort = $sort ?: $search->getDefaultSort();
        foreach ($sort as $field => $order) {
            if (is_array($order)) {
                foreach ($order as $value) {
                    $search->getQuery()->orderByRaw(snake_case($field) . ' != ?', [$value]);
                }
            } else {
                $search->getQuery()->orderBy(snake_case($field), $order);
            }
        }
    }