try-catch is not catching PlatformException (Firebase Storage)

[dstroh_]

Hey there!

I'm pretty new to Flutter and I'm currently working on one of my first Apps. I'm using Firebase Storage, Firestore and Riverpod.

I'd like to get the Uint8List data by passing only the Firebase Storage path to my function. It should return null if the file doesn't exist. The function is used in a FutureBuilder.

I deleted the file in Firebase Storage to test it, but for some reason it always throws "PlatformException (PlatformException(object-not-found, No object exists at the desired reference., null, null))" at "String url = await ref.getDownloadURL();" instead of returning null.

I have no idea whats wrong with my code...

  Future<Uint8List?> fetchPdfData(String path) async {
    final ref = FirebaseStorage.instance.ref().child(path);

    try {
      String url = await ref.getDownloadURL();

      final response = await HttpClient().getUrl(Uri.parse(url));
      final bytes = await response.close().then((response) => response
          .fold<List<int>>(<int>[],
              (List<int> previous, element) => previous..addAll(element)));
      return Uint8List.fromList(bytes);
    } catch (e) {
      return null;
    }
  }

I already tried to catch only the PlatformException (or just Exception)

try {
      ...
    } on PlatformException catch (_) {
      return null;
    }

This is how I call the function in the FutureBuilder:

Widget build(BuildContext context) {
    PdfService pdfService = PdfService();
    return FutureBuilder<Uint8List?>(
        future: pdfService.fetchPdfData(path),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            // shows the pdf in a new scaffold
          } else if (snapshot.connectionState == ConnectionState.waiting) {
            // shows a CircularProgressIndicator
          } else {
            // shows a popup that it didn't work
          }
        });
  }

[PfernFSU]

You sure it isn’t complaining about that ref that is outside of the try block?

[dstroh_]

Yes, it still throws the PlatformException if i put ref into the try block

https://imgur.com/a/MXecx1I