OEModule\OphCoCvi\controllers\DefaultController::getListFilter PHP Method

    protected function getListFilter()
    {
        $filter = array();
        // if POST, then a new filter is to be applied, otherwise retrieve from the session
        if ($this->request->isPostRequest) {
            foreach (array('date_from', 'date_to', 'subspecialty_id', 'site_id', 'consultant_ids', 'show_issued') as $key) {
                $val = $this->request->getPost($key, null);
                $filter[$key] = $val;
            }
        } else {
            if ($session_filter = $this->getApp()->session[static::$FILTER_LIST_KEY]) {
                $filter = $session_filter;
            }
        }
        // set the is filtered flag for the controller
        foreach ($filter as $val) {
            if ($val) {
                $this->is_list_filtered = true;
                break;
            }
        }
        // store filter for later use
        $this->getApp()->session[static::$FILTER_LIST_KEY] = $filter;
        return $filter;
    }