laravel dcat-admin upload multiple images

$form->multipleImage('images')->sortable()->compress(['width' => 750,'quality' => 90,])->uniqueName()
    ->saveAsString()->saving(function ($value)use($form){
    if ($form->isEditing() && request()->filled('_file_del_')) {
        if (ChapterImage::where('image_url', request()->input('_file_del_'))->delete() > 0) {
            return $form->response()->success('删除成功');
        }
        return $form->response()->error('删除失败');
    } else {
        if ($value) {
            $form->saved(function ()use($value,$form){
                $data       = json_decode($value);
                ChapterImage::whereIn('image_url', $data)->delete();//delete all
                $insertData = [];
                foreach ($data as $item) {
                    $insertData[] = [
                        'image_url'   => $item,
                        'chapter_id'  => $form->repository()->model()->id,
                    ];
                }
                \DB::table('chapter_images')->insert($insertData);
            });
        }
        return $form->response()->success('成功');
    }
})->customFormat(function ($value){
      if (!$value) {
          return;
      }
      return array_column($value,'image_url');
    });