public function renderSorter()
{
$sort = $this->dataProvider->getSort();
if ($sort === false || empty($sort->attributes) || $this->dataProvider->getCount() <= 0) {
return '';
}
/* @var $class LinkSorter */
$sorter = $this->sorter;
$class = ArrayHelper::remove($sorter, 'class', LinkSorter::className());
$sorter['sort'] = $sort;
$sorter['view'] = $this->getView();
return $class::widget($sorter);
}