utf8.decoder not working after latest Flutter Upgrade

Question

The class APIPostRequest was wroking all fine until a flutter upgrade hit and it shows an error of "The argument type 'Utf8Decoder' can't be assigned to the parameter type 'StreamTransformer'." while transforming HttpClientResponse's object into String using ...transform(utf8.decoder)...

class APIPostRequest {
  Future<String> apiRequest(String url, Map jsonMap) async {
    HttpClient httpClient = new HttpClient();
    HttpClientRequest request = await httpClient.postUrl(Uri.parse(url));
    request.headers.set('Accept', 'application/json');
    request.headers.set('Content-type', 'application/json');
    request.headers
        .set('Authorization', "Bearer " + UserConstants.userAccessToken);
    request.add(utf8.encode(json.encode(jsonMap)));
    HttpClientResponse response = await request.close();
    String reply = await response.transform(utf8.decoder).join();
    httpClient.close();
    return reply;
  }
}

Solution 1

See the corresponding breaking change announcement:

Error cases (and how to fix them):

If you see the following errors in your code, here's what you do to fix them:

• Error: "The argument type 'Utf8Decoder' can't be assigned to the parameter type 'StreamTransformer'."
  • How to fix: Use StreamTransformer.bind(Stream) instead of Stream.transform(StreamTransformer).
  • Example:
    • Before: foo.transform(utf8.decoder)...
    • After: utf8.decoder.bind(foo)...

Solution 2

Comment String reply = await utf8.decoder.bind(response).join();

and use the following code :

//String reply = await response.transform(utf8.decoder).join();
String reply;
request.close().then((response){
response.cast<List<int>>().transform(utf8.decoder).listen((content) {
    print (content);
    reply = content;
});

Comments

[10101010]

I guess it should work fine if you are on the stable channel

[blaze bnayak]

It was working fine just before the upgrades. Tried this solution stackoverflow.com/questions/56862020/… but it seems it is changing the expected response in some other string values

[10101010]

I did not get you. Does that solution not work you?

[DomingoMG]

This solution helped me thank you