using FutureBuilder to get Future<String> from firestore - flutter

Question

This is my code in which I want to display an email which is a Future and I will get it from my firestore.However, I am not sure how I will need to retrieve my value using FutureBuilder which I want to use as a string.
This is my method to get my email:
Future<String> getEmail() async {
String _email = (await FirebaseAuth.instance.currentUser()).email;
DocumentSnapshot snapshot = await _firestore.collection('users')
.document(_email)
.collection('met_with')
.document('email')
.get();
// print("data: ${snapshot.data}"); // might be useful to check
return snapshot.data['email']; // or another key, depending on how it's saved
}
this is my updated code:
#override
Widget build(BuildContext context) {
return Card(
elevation: 3.0,
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10.0)),
child: ListTile(
leading: CircleAvatar(
backgroundImage: AssetImage(imagePath),
),
trailing: Icon(Icons.more_horiz),
title: Text(
email,
style: TextStyle(
c #override
Widget build(BuildContext context) {
return Card(
elevation: 3.0,
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10.0)),
child: ListTile(
leading: CircleAvatar(
backgroundImage: AssetImage(imagePath),
),
trailing: Icon(Icons.more_horiz),
title: Text(
email,
style: TextStyle(
color: Colors.deepPurple[700],
fontWeight: FontWeight.bold,
),
),
subtitle: Text(infection),
onTap: () => showModalBottomSheet(
context: context,
builder: (builder) {
return FutureBuilder(
future: getEmail(),
builder: (BuildContext context, snapshot) {
if(snapshot.hasData){
if(snapshot.connectionState == ConnectionState.waiting){
return Center(
child: CircularProgressIndicator(),
);
}else{
return Padding(padding: EdgeInsets.symmetric(vertical: 50.0, horizontal: 10.0),
child: Column(
children: <Widget>[
BottomSheetText(
question: 'Email', result: snapshot.data['email']),
SizedBox(height: 5.0),
BottomSheetText(
question: 'Contact Time',result:"lol"),// getTimeStamp().toString()),
SizedBox(height: 5.0),
BottomSheetText(
question: 'Contact Location',
result: "help"),
SizedBox(height: 5.0),
BottomSheetText(question: 'Times Contacted', result: "lool",),
],
),
);
}
}else{
return CircularProgressIndicator();}
}
);
}
),
),
);
}
}
Here is my firebase database:
enter image description here

Answer 1

Your query is wrong, try following one.
Future<String> getEmail() async {
String _email = (await FirebaseAuth.instance.currentUser()).email;
var a = await Firestore.instance
.collection("met_with")
.where('email', isEqualTo:. _email )
.getDocuments();
return a.documents[0]['email'];
}
And to call this method you need futureBuilder.
FutureBuilder(
future: getEmail(),
builder: (BuildContext context, snapshot) {
if(snapshot.hasData){
if(snapshot.connectionState == ConnectionState.waiting){
return Center(
child: CircularProgressIndicator(),
);
}else{
return Center( // here only return is missing
child: Text(snapshot.data['email'])
);
}
}else if (snapshot.hasError){
return Text('no data');
}
return CircularProgressIndicator();
},
),

Answer 2

You need to use a FutureBuilder:
FutureBuilder(
future: getEmail(),
builder: (BuildContext context, snapshot) {
if(snapshot.hasData){
if(snapshot.connectionState == ConnectionState.waiting){
return Center(
child: CircularProgressIndicator(),
);
}else{
return Center( // here only return is missing
child: Text(snapshot.data['email'])
);
}
}else if (snapshot.hasError){
Text('no data');
}
return CircularProgressIndicator();
},
),
This way you can use the returned value of the method inside the build method. Also change the Future method to the following:
Future<String> getEmail() async {
String _email = (await FirebaseAuth.instance.currentUser()).email;
return await _firestore.collection('users')
.document(_email)
.collection('met_with')
.document('email')
.get();
}