public function postUpdateMediasPosition(Request $request)
 {
     $itemId = intVal($request->input('id'));
     $mediaId = intVal($request->input('mediaId'));
     $item = call_user_func(array($this->class_name, 'findOrFail'), $itemId);
     $media = Media::findOrFail($mediaId);
     $collection = $media->collection;
     $medias = $item->getMedias($collection);
     $oldPos = $media->position;
     $newPos = intVal($request->input('position'));
     if ($oldPos != $newPos) {
         if ($oldPos < $newPos) {
             $range = [$oldPos + 1, $newPos];
         } else {
             $range = [$newPos, $oldPos - 1];
         }
         // whereBetween does not exist for collections as Laravel 5.2!
         //$medias = $medias->whereBetween('position', $range);
         $rangeList = [];
         for ($i = $range[0]; $i <= $range[1]; ++$i) {
             $rangeList[] = $i;
         }
         $medias = $medias->whereIn('position', $rangeList);
         // increment and devrement does not exist for collections as Laravel 5.2!
         if ($oldPos < $newPos) {
             foreach ($medias as &$m) {
                 --$m->position;
                 $m->save();
             }
         } else {
             foreach ($medias as &$m) {
                 ++$m->position;
                 $m->save();
             }
         }
         $media->position = $newPos;
         $media->save();
     }
 }
 public function update(Request $request)
 {
     $id = $request->input('id', 0);
     $media = Media::findOrFail($id);
     $media->title = $request->input('title', 'tmp_name');
     $media->save();
 }