public function go()
 {
     $challenges = Challenge::getChallengesFrontend();
     $menu = array();
     foreach ($challenges as $challenge) {
         $link = array('id' => $challenge->id, 'title' => $challenge->title, 'url' => 'challenges/' . $challenge->pkg_name . '/index.php');
         array_push($menu, $link);
     }
     $this->addToView('list', $menu);
     $this->setViewTemplate('challenge_list.tpl');
     return $this->generateView();
 }
 public function go()
 {
     $username = $this->getLoggedInUser();
     $user = User::findByUserName($username);
     if (!$user) {
         return;
     }
     if (Session::isAdmin() || Session::isTeacher()) {
         $challenges = Challenge::getChallengesFrontend();
     } else {
         $challenges = Challenge::getChallengesAssigned($user->id);
     }
     $menu = array();
     foreach ($challenges as $challenge) {
         $link = array('id' => $challenge->id, 'title' => $challenge->title, 'url' => 'challenges/' . $challenge->pkg_name . '/index.php');
         array_push($menu, $link);
     }
     return $menu;
 }