Question 227653 in Flutter Question posted in
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Flutter: How can I add network check and showDialog on a Future function

I have below 2 methods in my Utility class: One for checking the network connection and on for showing the progress dialog.

static Future<bool> isInternet() async
  {
    bool result = await InternetConnectionChecker().hasConnection;
    return result;
  }

  static ShowProgress(BuildContext context) {
    return showDialog(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return Center(
            child: SpinKitRotatingCircle(color: const Color(0xff2799fa), size: 60.0, ),
          );
        });
  }

I need to apply it on the below API call section:

class _UserDetailsState extends State<UserDetails> {
  ProfileResponse? profileResponse;
  Future<void> fetchData() async {
    try {
      //Utility.ShowProgress(context);
      final response = await getProfileDetails();
      if (response.statusCode == 200) {
        Map<String, dynamic> parsedData = jsonDecode(response.body);
        setState(() {
          profileResponse = ProfileResponse.fromJson(parsedData);
        });
      } else {
        // setState(() {
        //   _data = 'Error: ${response.statusCode}';
        // });
      }
    } catch (error) {
      // setState(() {
      //   _data = 'Error: $error';
      // });
    }
    //Navigator.of(context).pop();
  }

  @override
  void initState() {
    fetchData();
  }
  
  @override
Widget build(BuildContext context) {
return Container(
     )
}
  
  Future<http.Response> getProfileDetails() async{
    if(await Utility.isInternet()){
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    //reading values from SharedPreferences and calling the API
    final String url = My API Path;
    final response = await http.get(Uri.parse(url));
    return response;
    }
    else{
      //show no network alert
    }
}

I added ProgressDialog in the fetchData(), like the commented code in the code, but it is not showing in the UI when calling the API.

Also I have added the network check on the getProfileDetails(), but it is showing below error.

The body might complete normally, causing ‘null’ to be returned, but the return type, ‘FutureOr’, is a potentially non-nullable type. Try adding either a return or a throw statement at the end.

How can I fix these 2 issues?

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    The fixed code with progress dialog and network check adding below:

    Future<http.Response?> getProfileDetails() async
{
    if(await Utility.isInternet())
    {
      Utility.ShowProgress(context);
      //reading values from SharedPreferences and calling the API
      final String url = My API Path;
      final response = await http.get(Uri.parse(url));
      Navigator.of(context).pop();
      return response;
    }
    else
    {
      Utility.showToastMessage("No internet connection!",Toast.LENGTH_SHORT,
          ToastGravity.CENTER, Colors.white, 16.0 );
      return null;
    }
}

  2. 0

    Whenever you define a method that has some sort of expected output, your code should return the exact same type you defined or an error.

    In your code you have declared a Future like this:

     Future<http.Response> getProfileDetails() async{

    You should always return a Future<http.Response>.
    However, when the first If condition is not True, there is nothing to be returned, resulting in your error.

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