StreamBuilder returns no value - Flutter

Question

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']),

MickaelHrndz · Accepted Answer · 2020-08-16 15:19:45Z

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),

Your answer is right! It's just that I'm starting to learn flutter now, and I still have doubts. Now, how could I get real-time responses from the firestore? I had used StreamBuilder for this purpose.
I think your code is correct. You get updates with snapshots(). just add return before StreamBuilder and add _newMoveToApoio(uidProp) where you want it in your widget tree.
Sorry, I couldn't understand. Can you give me an example, please?
I tried to use StreamBuilder as you indicated, but it didn't work ... The first way using get (), is working.

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