The undefined variable warning suppressed

~dev_rating/application/classes/Controller/Handler/AdmStudents.php

 <?php defined('SYSPATH') or die('No direct script access.');
 
-class SortingOptions { //extends SplEnum {
+abstract class SortingOptions { //extends SplEnum {  // todo: think about usage & file system
     //const __default = self::Name;
 
     const Name = 0;
@@ -117,6 +117,8 @@ class Controller_Handler_AdmStudents extends Controller_Handler {
 
         public function action_getStudentsList($option = SortingOptions::Name)
         {
+            $twig = Twig::factory('admin/students/handler/listOutput');
+
             $success = false;
             $facultyID = $this->post->offsetGet('facultyID');
             $gradeID = $this->post->offsetGet('gradeID');
@@ -128,17 +130,17 @@ class Controller_Handler_AdmStudents extends Controller_Handler {
                 -> rule('gradeID', 'digit')
                 -> rule('GroupID', 'not_empty')
                 -> rule('groupID', 'digit');
+
             if($this->post->check()) {
 //                $result = $this->commonModel->GetStudentsList($this->user['UserID'], $facultyID , $gradeID, $groupID);
                 $result = Model_Students::create()->byFaculty($facultyID , $gradeID, $groupID)->asArray();
                 if (!empty($result)) {
+                    $twig->List = $result;
                     $success = true;
                 }
 
             }
             //$this->response->body(json_encode($data));
-            $twig = Twig::factory('admin/students/handler/listOutput');
-            $twig->List = $result;
             $twig->Success = $success;
             $this->response->body($twig);
         }