Getting null value (Firestore query result) in Flutter app - firebase

Question

I have an application and In this i'm making a query for get user details by the e-mail account.
I'm using Future class to get data and fill my variable but the widget Text always show null value.
Please let me now if i am doing something wrong.
class _HomePageAppState extends State<HomePageApp> {
String _emailUsuario;
Usuario usuario;
void initState() {
super.initState();
Autenticacao().getCurrentUser().then((user) {
setState(() {
if (user != null) {
_emailUsuario = user.email.toString(); //the user email is returnig correctly
recuperarDadosUsuarioFirebase().then((ds) {
usuario = Usuario(
email: _emailUsuario,
nome: ds['nome'] != null ? ds['nome'] : null,
);
});
}
});
});
}
Future<DocumentSnapshot> recuperarDadosUsuarioFirebase() async {
DocumentSnapshot ds;
await Firestore.instance
.collection('usuarios')
.document(_emailUsuario)
.get()
.then((DocumentSnapshot _ds) {
ds = _ds;
});
return ds;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: Container(
color: Colors.white10,
child: ListView(
children: <Widget>[
Text('Bem vindo ${usuario.nome} !!!'),
],
),
),
);
}
}

Answer 1

U might want to use Future Builder for such async work cause build method was called before usuario is assign so like this :
FutureBuilder(
future: getCurrentUser(),
builder: (context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Center(child: CircularProgressIndicator());
}
// after getting data
},
);
Method getCurrentUser() needs to be created :)