how to pass variables future function to extend statefulwidget - flutter

Question

in my code in HomeeScreen class I call Future function , In that future function fecth data from API and display in console nicely. print(datas[0].field2Value); this is the code line.And aslo that is the boolean value I want to get that value to class _HomeeScreenState extends State and deaclare to a bool variable. like this
bool field2Value = datas[0].field2;
but then show this error.
code
class _HomeeScreenState extends State<HomeeScreen> {
Timer? timer;
Future<List<DataList>>? future;
#override
void initState() {
super.initState();
timer = Timer.periodic(
Duration(seconds: 15), (Timer t) => isDoctorActive(widget.id));
}
bool field2Value = datas[0].field2Value;
final String url = 'https://exampleapi.com/api/calls/?check=';
Future<List<DataList>> isDoctorActive(String id) async {
Response response = await get(Uri.parse(url + id));
if (response.statusCode == 200) {
print("apicall : " + id);
Map<String, dynamic> json = jsonDecode(response.body);
Map<String, dynamic> body = json['data'];
List<DataList> datas = [DataList.fromJson(body)];
print(datas[0].field2Value);
return datas;
} else {
throw ('cannot fetch data');
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: ElevatedButton(
onPressed: field2Value ? joinVideoRoom : null, child: Text("Join")),
),
);
}
Future<void> joinVideoRoom() async {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => NextScreen(),
));
}
}

Answer 1

Why don't you just accept another argument in your function? meaning:
isActive(String id, myArgument)
class _HomeeScreenState extends State<HomeeScreen> {
bool field2Value = datas[0].field2;
final String url = 'https://exampleapi.com/api/calls/?check=';
Future<List<DataList>> isActive(String id, field2) async {
....
print(field2)
}