# upload method Null safety

Future<List<String>> upload(

1. List<File> images

)

로컬 이미지 파일 여러장을 카카오스토리에 업로드

## Implementation

    Future<List<String>> upload(List<File> images) async {
      return ApiFactory.handleApiError(() async {
        List<MultipartFile> files = await Future.wait(images.map((image) async =>
            await MultipartFile.fromFile(image.path,
                filename: image.path.split("/").last)));
        Map<String, MultipartFile> data = files.asMap().map((index, file) {
          return MapEntry("${Constants.file}_${index + 1}", file);
        });
        final response = await _dio.post(Constants.scrapImagesPath,
            data: FormData.fromMap(data));
        var urls = response.data;
        if (urls is List) return urls.map((url) => url as String).toList();
        throw KakaoClientException("Response should be an array.");
      });
    }