/**
  * Updates an existing Categories model.
  * If update is successful, the browser will be redirected to the 'view' page.
  * @param integer $id
  * @return mixed
  */
 public function actionUpdate($id)
 {
     if (\Yii::$app->user->isGuest) {
         return $this->goHome();
     }
     $model = $this->findModel($id);
     $indicatorsAvailable = IndicatorNames::find()->select(['name', 'id'])->indexBy('id')->column();
     $indicatorsPresent = $model->getIndicators()->select(['name', 'id'])->indexBy('id')->column();
     foreach ($indicatorsPresent as $value) {
         if (($key = array_search($value, $indicatorsAvailable)) !== false) {
             unset($indicatorsAvailable[$key]);
         }
     }
     if ($model->load(Yii::$app->request->post()) && $model->save()) {
         CategoriesIndicators::deleteAll('id_categories = ' . $id);
         foreach (Yii::$app->request->post()['Categories']['indicators'] as $id_indicator) {
             $catInd = new CategoriesIndicators();
             $catInd->id_indicator_names = $id_indicator;
             $catInd->id_categories = $model->id;
             $catInd->save();
         }
         return $this->redirect(['view', 'id' => $model->id]);
     } else {
         return $this->render('update', ['model' => $model, 'indicatorsAvailable' => $indicatorsAvailable, 'indicatorsPresent' => $indicatorsPresent]);
     }
 }