Null value from a provider that return data after hot reload in flutter

Question

I am getting a null printed and my widget not building as expected due to a null return from a provider. The funny thing is that when i hot reload the app the provider returns the value expected. This particular provider is of type position. i am using the geolocator api to get a users position. I have tried using a safe null return with no hope of solving the issue like so

  @override
  Widget build(BuildContext context) {
   Position coordinates=Provider.of<Position>(context);
    print(coordinates);
    if(coordinates!=null){

   .... some returned widget here...
    }else{
      return circularProgress();
    }
   }
}

The app returns the loading indicator circularProgress() but when i hot reload, the preceeding widget is returned. What could i be doing wrong?

Answer 1

I am using location plugin but I had same issue. I am sharing my solution.

class LocationRepository {
  UserLocation userLocation;
  Location location = Location();  

Future<UserLocation> getCurrentLocation() async {        
    var currentLocation = await location.getLocation();
    userLocation =
    UserLocation(currentLocation.latitude, currentLocation.longitude);}

The class is using for get first location of user. In this way I have a location data when page which include location process is loading.

enum LocationProviderStatus {
  Initial,
  Loading,
  Success,
  Error,
}

I have enum in my Provider Class. I am checking to data is loaded whether or not.

Future<void> getLocation() async {
    try {
    _updateStatus(LocationProviderStatus.Loading);
    _userLocation = await _locationRepository.getCurrentLocation()
    _updateStatus(LocationProviderStatus.Success);
    } catch{}
}

When open the page, call this method.

class _LocationScreenState extends State<LocationScreen> {


Location location;
LocationData currentLocation;

  @override
  void initState() {
    location = new Location();
    location.onLocationChanged.listen((LocationData cLoc) {
      currentLocation = cLoc;

    });

    super.initState();
  }


Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(),
        body: Consumer(builder: (context, LocationProvider provider, _) {
          if (provider.status == LocationProviderStatus.Loading ||
              provider.status == LocationProviderStatus.Initial) {
            return Center(child: CircularProgressIndicator());
          } else if (provider.status == LocationProviderStatus.Success) {

//your widget }

Using Enum Status , page is waiting until it gets location data. You can set a timeout if you don't want to wait for a long time.