/**
  * Update gallery images.
  * @return void
  */
 private function updateImages()
 {
     $old = [];
     foreach ($this->object->images as $image) {
         $old[$image->id] = $image;
     }
     // insert/update
     foreach ($this->images as $data) {
         $id = null;
         if (!empty($data['id'])) {
             $id = $data['id'];
         }
         if (array_key_exists($id, $old)) {
             $image = $old[$id];
             unset($old[$id]);
         } else {
             $image = new GalleryImage();
             $image->gallery_id = $this->object->id;
         }
         $image->setAttributes($data);
         Yii::$app->storage->storeObject($image);
         $image->save(false);
     }
     // delete
     foreach ($old as $image) {
         Yii::$app->storage->removeObject($image);
         $image->delete();
     }
 }
 /**
  * Images relation
  * @return ActiveQuery
  */
 public function getImages()
 {
     return $this->hasMany(GalleryImage::className(), ['gallery_id' => 'id']);
 }