DiscussionModel::removeSort PHP Method

    public static function removeSort($key)
    {
        if (val($key, self::$allowedSorts)) {
            unset(self::$allowedSorts[$key]);
        }
    }

 /**
  * Default all discussions view: chronological by most recent comment.
  *
  * @since 2.0.0
  * @access public
  *
  * @param int $Page Multiplied by PerPage option to determine offset.
  */
 public function index($Page = false)
 {
     $this->allowJSONP(true);
     // Figure out which discussions layout to choose (Defined on "Homepage" settings page).
     $Layout = c('Vanilla.Discussions.Layout');
     switch ($Layout) {
         case 'table':
             if ($this->SyndicationMethod == SYNDICATION_NONE) {
                 $this->View = 'table';
             }
             break;
         default:
             // $this->View = 'index';
             break;
     }
     Gdn_Theme::section('DiscussionList');
     // Remove score sort
     DiscussionModel::removeSort('top');
     // Check for the feed keyword.
     if ($Page === 'feed' && $this->SyndicationMethod != SYNDICATION_NONE) {
         $Page = 'p1';
     }
     // Determine offset from $Page
     list($Offset, $Limit) = offsetLimit($Page, c('Vanilla.Discussions.PerPage', 30), true);
     $Page = PageNumber($Offset, $Limit);
     // Allow page manipulation
     $this->EventArguments['Page'] =& $Page;
     $this->EventArguments['Offset'] =& $Offset;
     $this->EventArguments['Limit'] =& $Limit;
     $this->fireEvent('AfterPageCalculation');
     // Set canonical URL
     $this->canonicalUrl(url(ConcatSep('/', 'discussions', PageNumber($Offset, $Limit, true, false)), true));
     // We want to limit the number of pages on large databases because requesting a super-high page can kill the db.
     $MaxPages = c('Vanilla.Discussions.MaxPages');
     if ($MaxPages && $Page > $MaxPages) {
         throw notFoundException();
     }
     // Setup head.
     if (!$this->data('Title')) {
         $Title = c('Garden.HomepageTitle');
         $DefaultControllerRoute = val('Destination', Gdn::router()->GetRoute('DefaultController'));
         if ($Title && $DefaultControllerRoute == 'discussions') {
             $this->title($Title, '');
         } else {
             $this->title(t('Recent Discussions'));
         }
     }
     if (!$this->Description()) {
         $this->Description(c('Garden.Description', null));
     }
     if ($this->Head) {
         $this->Head->AddRss(url('/discussions/feed.rss', true), $this->Head->title());
     }
     // Add modules
     $this->addModule('DiscussionFilterModule');
     $this->addModule('NewDiscussionModule');
     $this->addModule('CategoriesModule');
     $this->addModule('BookmarkedModule');
     $this->setData('Breadcrumbs', array(array('Name' => t('Recent Discussions'), 'Url' => '/discussions')));
     // Set criteria & get discussions data
     $this->setData('Category', false, true);
     $DiscussionModel = new DiscussionModel();
     $DiscussionModel->setSort(Gdn::request()->get());
     $DiscussionModel->setFilters(Gdn::request()->get());
     $this->setData('Sort', $DiscussionModel->getSort());
     $this->setData('Filters', $DiscussionModel->getFilters());
     // Check for individual categories.
     $categoryIDs = $this->getCategoryIDs();
     $where = array();
     if ($categoryIDs) {
         $where['d.CategoryID'] = CategoryModel::filterCategoryPermissions($categoryIDs);
     } else {
         $DiscussionModel->Watching = true;
     }
     // Get Discussion Count
     $CountDiscussions = $DiscussionModel->getCount($where);
     if ($MaxPages) {
         $CountDiscussions = min($MaxPages * $Limit, $CountDiscussions);
     }
     $this->setData('CountDiscussions', $CountDiscussions);
     // Get Announcements
     $this->AnnounceData = $Offset == 0 ? $DiscussionModel->GetAnnouncements($where) : false;
     $this->setData('Announcements', $this->AnnounceData !== false ? $this->AnnounceData : array(), true);
     // RSS should include announcements.
     if ($this->SyndicationMethod !== SYNDICATION_NONE) {
         $Where['Announce'] = 'all';
     }
     // Get Discussions
     $this->DiscussionData = $DiscussionModel->getWhereRecent($where, $Limit, $Offset);
     $this->setData('Discussions', $this->DiscussionData, true);
     $this->setJson('Loading', $Offset . ' to ' . $Limit);
     // Build a pager
     $PagerFactory = new Gdn_PagerFactory();
     $this->EventArguments['PagerType'] = 'Pager';
     $this->fireEvent('BeforeBuildPager');
     if (!$this->data('_PagerUrl')) {
         $this->setData('_PagerUrl', 'discussions/{Page}');
     }
     $queryString = DiscussionModel::getSortFilterQueryString($DiscussionModel->getSort(), $DiscussionModel->getFilters());
     $this->setData('_PagerUrl', $this->data('_PagerUrl') . $queryString);
     $this->Pager = $PagerFactory->GetPager($this->EventArguments['PagerType'], $this);
     $this->Pager->ClientID = 'Pager';
     $this->Pager->configure($Offset, $Limit, $this->data('CountDiscussions'), $this->data('_PagerUrl'));
     PagerModule::Current($this->Pager);
     $this->setData('_Page', $Page);
     $this->setData('_Limit', $Limit);
     $this->fireEvent('AfterBuildPager');
     // Deliver JSON data if necessary
     if ($this->_DeliveryType != DELIVERY_TYPE_ALL) {
         $this->setJson('LessRow', $this->Pager->toString('less'));
         $this->setJson('MoreRow', $this->Pager->toString('more'));
         $this->View = 'discussions';
     }
     $this->render();
 }