/**
  * Display class in which user attend. 
  * @param  [String] $id [description]
  * @return [type]     [description]
  */
 function getClass($user_id)
 {
     $result = array();
     if (isset($user_id)) {
         $model = new User_Class_Model();
         $class_id = $model->selectWhere(array('class_id'), "user_id = " . "'{$user_id}'");
         if (isset($class_id)) {
             $class_model = new Class_Room_Model();
             foreach ($class_id as $key => $value) {
                 $record = $class_model->selectWhere('*', "id = " . $value['class_id']);
                 array_push($result, $record[0]);
             }
         }
         if (isset($result)) {
             echo json_encode($result);
         }
     }
 }
 /**
  * Get student attend to class
  * @param  [type] $class_id [description]
  * @return [type]           [description]
  */
 function getStudent($class_id)
 {
     $result = array();
     $owner_id = $this->model->selectWhere(array('owner_id'), "id = " . "'{$class_id}'");
     if (isset($class_id)) {
         $UserClassModel = new User_Class_Model();
         $user_id = $UserClassModel->selectWhere(array('user_id'), "class_id = " . "'{$class_id}'");
         if (isset($user_id)) {
             foreach ($user_id as $key => $value) {
                 $UserModel = new User_Model();
                 $user_id = $value['user_id'];
                 if ($owner_id[0]['owner_id'] == $user_id) {
                     continue;
                 }
                 $user = $UserModel->selectWhere('*', "\tid = " . "'{$user_id}'");
                 array_push($result, $user);
             }
             echo json_encode($result[0]);
         }
     } else {
         echo json_encode('failed');
     }
 }