CODEWITHSUNDEEP
fluttergoogle-cloud-firestore
JohnSan
JohnSan

Reputation: 53

StreamBuilder returns no value - Flutter

I am trying to return location values ​​with StreamBuilder, but I have not been successful. In debug, he doesn't even run the builder. I can't find the problem.

Here I create StreamBuilder, to bring the location

_newMoveToApoio(String uidProp) {
    StreamBuilder(
        stream: Firestore.instance
            .collection('tracker')
            .document(uidProp)
            .snapshots(),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return new Center(
              child: CircularProgressIndicator(),
            );
          } else {
            var trackerDocument = snapshot.data;
            double latitude = trackerDocument['latitude'];
            double longitude = trackerDocument['longitude']; 

            _controller.animateCamera(CameraUpdate.newCameraPosition(
                CameraPosition(
                    target: LatLng(latitude, longitude), zoom: 18.0)));
            setState(() {
              _markers.add(
                Marker(
                  draggable: false,
                  markerId: MarkerId("1"),
                  position: LatLng(latitude, longitude),
                  infoWindow: InfoWindow(
                      title: "João Marcelo", snippet: "Sua Localização Atual"),
                  icon: _markerIconApoio,
                ),
              );
            });
          }
        });
  }

Here I make the call in a bottomsheet, passing the 'uid'

onTap: () =>  _newMoveToApoio(snapshot.data[index].data['uidProp']),

Upvotes: 0

Views: 113

Answers (1)

MickaelHrndz
MickaelHrndz

Reputation: 3832

I think you misunderstand what StreamBuilder is for. It is a widget to be used in a widget tree. But you call it from an onTap which just executes the function. You may want something more like this :

_newMoveToApoio(String uidProp) async {
  var snapshot = await Firestore.instance
            .collection('tracker')
            .document(uidProp)
            .get();
  // do your business logic here
}

EDIT : To use the StreamBuilder inside the tree, first return it :

Widget _newMoveToApoio(String uidProp) {
  return StreamBuilder(
    // the rest of the function

and then inside your build method :

RandomWidget(
  child: _newMoveToApoio(uidProp),

Upvotes: 1

Related Questions