Exception: Null check operator used on a null value

[Throvn]

First of all... Love this package. Thank you for all of the work you put in so far.

Now to my problem: Everything worked like a charm, but since the barcode detection process is pretty heavy, I want to outsource this process in a seperate Isolate. Here is my stripped (pseudo) code:

Future<void> callerFunction() async {
    String path = "getting path from camera (file is XFile)";
    await compute(doDetection, path);
}

FutureOr<String> doDetection(String imagePath) async {
    // initialize barcode detector
    final BarcodeDetector _barcodeDetector =
      GoogleVision.instance.barcodeDetector();

    // detect barcodes in camera image
    final GoogleVisionImage visionImage =
        GoogleVisionImage.fromFilePath(imagePath);

    // the error is thrown in 
    final List<Barcode> barcodes =
        await _barcodeDetector.detectInImage(visionImage);

    // other code here, but this code does not get executed after error is thrown
}

After the refactoring I get the following error: Exception: Null check operator used on a null value After a bit of digging, I am pretty sure that this is because of the following line:

final List<Barcode> barcodes =
        reply!.map((barcode) => Barcode._(barcode)).toList();

The reply is null.

So is it possible to do the recognition in a seperate Isolate? or how can I fix this issue? Any help or hints is appreciated. If you need more information just let me know :).

Best regards, Louis :)

[Throvn]

Did some more digging, and as it turns out, it is not possible to call platform specific through platform channels in isolates. Found this issue which is still open: https://github.com/flutter/flutter/issues/13937

So I the best workaround to my is to let the main isolate call the platform channels.

[Throvn]

After testing this with other plugins who also use MethodChannels, I can confirm that this is not an issue with the library but rather with Isolates. Closing this issue now.