How to get user id from firebase auth as string? - firebase

Question

I'm trying to insert data to firestore with the authenticated user id as the document id but i got null from the parameter.
Please take a look at my script.
void didChangeDependencies() {
uid = '';
super.didChangeDependencies();
}
Future _fetchUID() async {
var auth = AuthProvider.of(context).auth;
return await auth.getCurrentUser().then((user) => _uid = user.uid);
}
_validateAndSubmit() async {
setState(() {
_errorMessage = '';
_isLoading = true;
});
if (_validateAndSave()) {
try {
_fetchUID();
await Report.create(_uid, _suspectName, _plateNumber, _civilizationId,
_drivingLicenseId, _clause, _description);
return Navigator.of(context).pop();
} catch (e) {
setState(() {
_isLoading = false;
_errorMessage = e.message;
});
print(_errorMessage);
throw Exception(e);
}
}
}
In this method below you can see that I have already tried to set the _uid, but I still cannot get the _uid value.
Future _fetchUID() async {
var auth = AuthProvider.of(context).auth;
return await auth.getCurrentUser().then((user) => _uid = user.uid);
}
This is how the getCurrentUser() method looks like.
Future<FirebaseUser> getCurrentUser() async {
FirebaseUser user = await _firebaseAuth.currentUser();
return user;
}
Am I doing it wrong?

Answer 1

First of all, you mixed the Future.then syntax and the async await syntax.
You should probably write your method this way:
void _fetchUID() async {
var auth = AuthProvider.of(context).auth;
_uid = (await auth.getCurrentUser()).uid;
}
If _uid is still null for you after calling _fetchUID this way, then you are simply not signed in, meaning that there is no FirebaseUser as you first need to sign in.
In your _validateAndSubmit method, you also first need to await your _fetchUID call, otherwise it will pass _uid before it has been assigned a value.
...
try {
await _fetchUID();
await Report.create(_uid, ..);
...