snapshot.ConnectionState always waiting - dart

Question

In a FutureBuilder, snapshot.ConnectionState is always waiting, but the future function completed successfully. While in a different page the same block of code works and the ConnectionState transitions from waiting to done.
The future function:
Future getDoctors() async {
var res = await http.get(globals.domain + "users/docs/");
var resBody = json.decode(utf8.decode(res.bodyBytes));
print(res.statusCode);
if (res.statusCode == 200) {
if (mounted) {
setState(() {
doctors = resBody;
});
}
}
}
The future builder:
FutureBuilder(
future: getDoctors(),
builder: (BuildContext context, snapshot) {
print(snapshot);
}
)
Actual result:
AsyncSnapshot<dynamic>(ConnectionState.waiting, null, null)
Expected result: transiton to AsyncSnapshot<dynamic>(ConnectionState.done, null, null)
EDIT1:
while debugging noticed that the future function getDoctors() is called periodically, I guess that's why the snapshot is always waiting

Answer 1

Calling setState causes the widget tree to be rebuild. Therefore, when the FutureBuilder is rebuilt, the getDoctors() function is invoked again, causing an infinite loop (getDoctors()->setState()->rebuild->getDoctors()...)
The solution is to either remove setState from the getDoctors method or invoke getDoctors() once in the initState() method, store the Future and pass it to the FutureBuilder, thus ensuring that it is only done once.
Future _doctorsFuture;
initState() {
...
_doctorsFuture = getDoctors();
}
.
.
// Somewhere in build()
FutureBuilder(
future: doctorsFuture,
builder: (BuildContext context, snapshot) {
print(snapshot);
}
),

Answer 2

You need to return the value from the Future to finish the connection. Change your Future to something like this:
Future<dynamic> getDoctors() async {
var res = await http.get(globals.domain + "users/docs/");
if (res.statusCode == 200) {
return json.decode(utf8.decode(res.bodyBytes));
}
return null;
}
And change your FutureBuilder to this:
FutureBuilder(
future: getDoctors(),
builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
print(snapshot);
if (snapshot.connectionState == ConnectionState.done && snapshot.hasData && snapshot.data != null) {
return Center(...);
}
return Center(child: CircularProgressIndicator());
},
)
Please modify to match your variables and classes.

Answer 3

Change the return of the Future like:
`Future<String> getDoctors() async{
var res = await http.get(globals.domain + 'users/docs/');
var resBody = json.decode(utf8.decode(res.bodyBytes));
if (res.statusCode == 200) {
if (mounted) {
setState(() {
doctors = resBody;
});
}
}
}`
and the FutureBuilder:
`FutureBuilder(
future: getDoctors(),
builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
break;
case ConnectionState.waiting:
return CircularProgressIndicator(
color: Colors.black54,
strokeWidth: 2,
);
case ConnectionState.active:
break;
case ConnectionState.done:
return Container(/*here write your return code*/);
}
return Text('Some error ocurred try getDoctor');
},
);`