I want to check if a user exists after login. I wrote the code below:
checkIfUserExists() async {
await Firebase.initializeApp();
FirebaseAuth.instance.authStateChanges().listen((User? user) {
if (user == null) {
print('User is currently signed out!');
return false;
} else {
print('User is signed in!');
return true;
}
});
}
The function can't return a boolean because it isn't a void as expected by the function. I need (to get the date from firebase authentication) a async function. Is there a way to get a return boolean from my function above?
The authStateChanges() method returns a Stream, while an async method must return a Future.
Given the name checkIfUserExists, it seems you only care about the current value, in which case it's easier to use the currentUser property instead:
checkIfUserExists() async {
await Firebase.initializeApp();
var user = FirebaseAuth.instance.currentUser;
if (user == null) {
print('User is currently signed out!');
return false;
} else {
print('User is signed in!');
return true;
}
}
If you call this code while the app is just started, currentUser may still be nil, as Firebase checks the user's credentials again at this point. If you want to wait for Firebase to finish this check, and get the user after that, you can get the first event from the authStateChanges() stream:
checkIfUserExists() async {
await Firebase.initializeApp();
var user = await FirebaseAuth.instance.authStateChanges().first();
if (user == null) {
print('User is currently signed out!');
return false;
} else {
print('User is signed in!');
return true;
}
}
bool checkUserExist()=>FirebaseAuth.instance.currentUser!=null;
My app workes with Firebase and Flutter. When reload() is launched, I get this error :
"No implementation found for method User#reload on channel plugins.flutter.io/firebase_auth"
All other firebase functions work, multidexEnabled is true
void main() {
WidgetsFlutterBinding.ensureInitialized();
runApp(MyApp());
}
Method :
Future<bool> reloadFirebase({required BuildContext context}) async {
bool _isUserStillConnected = true;
try {
await _firebaseAuth.currentUser?.reload();
User? _user = currentUser;
if(_user == null) {
_isUserStillConnected = false;
showDisconnectedDialog(context: context);
}
} on FirebaseAuthException catch(e) {
_isUserStillConnected = false;
showDisconnectedDialog(context: context);
}
return _isUserStillConnected;
}
call :
ListTile(
onTap: () async {
bool _isUserStillConnected = await AuthenticationProvider().reloadFirebase(context: context);
if(_isUserStillConnected) {
Navigator.of(context).pushNamed(
PAGE_ROOM,
arguments: _roomModels[index],
);
}
},
The error suggests that something went wrong with the authentication, so please try the following possible solutions:
Make sure that you have properly set up the sign-up method in the authentication tab of your firebase console
Depending on your FB version in yaml file, make sure to import firebase_core
Check for plugin conflicts / try to use the latest versions from pub.dev
If it has to do something with the reload() function, maybe try the solution from here, as it might be better for your case: https://stackoverflow.com/a/64899979/15117201
When I click on verification link from my email , it opens my app running in background but didChangeAppLifecycleState method returns data as null and deepLink as set in firebase instead of the whole emailLink from my email, resulting in SignInWithEmailAndLink to fail as its supposed to match email address entered in widget from the link recieved.
Here's the code taken from this article https://medium.com/firebase-developers/dive-into-firebase-auth-on-flutter-email-and-link-sign-in-e51603eb08f8 :-
1.didChangeAppLifecycleState method
#override
void didChangeAppLifecycleState(AppLifecycleState state) async {
if (state == AppLifecycleState.resumed) {
final PendingDynamicLinkData data =
await FirebaseDynamicLinks.instance.getInitialLink();
if( data?.link != null ) {
handleLink(data?.link);
}
FirebaseDynamicLinks.instance.onLink(
onSuccess: (PendingDynamicLinkData dynamicLink) async {
final Uri deepLink `enter code here`= dynamicLink?.link;
handleLink(deepLink);
}, onError: (OnLinkErrorException e) async {
print('onLinkError');
print(e.message);
});
}
}
handleLink method
void handleLink(Uri link) async {
if (link != null) {
final User user = (await _auth.signInWithEmailAndLink(
email: _userEmail,
link: link.toString(),
))
.user;
if (user != null) {
setState(() {
_userID = user.uid;
_success = true;
});
} else {
setState(() {
_success = false;
});
}
} else {
setState(() {
_success = false;
});
}
setState(() {});
}
main method (initializing firebase)
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
Note: - Deeplink is a concept still new to me in flutter, so I have set it randomly in firebase. My register page has a WidgetsBindingObserver to help resume app lifecycle state. My signup and sign in code is in an email widget and I'm not using forms to validate my textfields.
it seems that after you signin with email link the firebase instance has been not updated before checking auth.SigninWithEMailLink() you need to update it in firebase instance like this
var user= await auth.currentUser();
await user.reload();
user=await auth.currentUser();
if still you are facing problem please provide some more code to let me understand your issue properly
I am new to Flutter/Dart but I have been trying to figure out the DB rules for a project that I am working on. I know that there are numerous posts on SO about Firebase DB rules but everything that I have found and tried has not worked. In the particular case below I want anyone to be able to read the data but only the author to be able to write and edit it. I set the Doc ID to be the uid and that works fine with permissions removed but I cannot get anything to work when I add restricted rules. What am I doing wrong?
Stack Trace Message
I/flutter (17900): PlatformException(Error performing setData, PERMISSION_DENIED: Missing or insufficient permissions., null)
E/flutter (17900): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: setState() called after dispose(): _RegisterState#1360e(lifecycle state: defunct, not mounted)
My Firebase Rules:
service cloud.firestore {
match /databases/{database}/documents {
match /brews/{userId} {
allow read: if request.auth.uid != null;
allow write: if request.auth.uid == userId;
}
}
}
Database Code
class DatabaseService {
final String uid;
DatabaseService({this.uid});
//Collection reference
final CollectionReference brewCollection =
Firestore.instance.collection('brews');
Future updateUserData(String sugars, String name, int strength) async {
return await brewCollection.document(uid).setData({
'sugars': sugars,
'name': name,
'strength': strength,
});
}
//brew list from snapshot
List<Brew> _brewListFromSnapshot(QuerySnapshot snapshot) {
return snapshot.documents.map((doc) {
return Brew(
name: doc.data['name'] ?? '',
strength: doc.data['strength'] ?? 0,
sugars: doc.data['sugars'] ?? '0',
);
}).toList();
}
//userData from snapshot
UserData _userDataFromSnapshot(DocumentSnapshot snapshot) {
return UserData(
uid: uid,
name: snapshot.data['name'],
sugars: snapshot.data['sugars'],
strength: snapshot.data['strength'],
);
}
//Get the collection stream
Stream<List<Brew>> get brews {
return brewCollection.snapshots().map(_brewListFromSnapshot);
}
//get user doc stream
Stream<UserData> get userData {
return brewCollection.document(uid).snapshots().map(_userDataFromSnapshot);
}
}
Authentication Code:
class Authenticate extends StatefulWidget {
#override
_AuthenticateState createState() => _AuthenticateState();
}
class _AuthenticateState extends State<Authenticate> {
bool showSignIn = true;
void toggleView() {
setState(() {
showSignIn = !showSignIn;
});
}
#override
Widget build(BuildContext context) {
if (showSignIn) {
return SignIn(toggleView: toggleView);
} else {
return Register(toggleView: toggleView);
}
}
}
Your rules are correct, and your update function is correct. Your authentication code doesn't show us if you perform a firebase auth login though.
The only thing that could stop it from working is if you are not logged in (authenticated via firebase authentication) OR you passed the wrong uid String to your DatabaseService class. If that's the case you wont have a request.auth.uid so the rule will fail.
You can test your rules in the console, or you can try isolate the exact payload in your code to provide us more info.
My Idea:
I want to use the Firebase Auth Plugin in Flutter to register the users.
But before they can access the App, they have to verify their Email address.
Therefor I push the Firebase users after registration to a verification screen. This is just a loading screen which tells the user that he has to verify his email.
But now: How can I continuously listen, if the users email is verified or not and send him (when true) to the Homescreen?
I'm new to Flutter and I don't know if I have to use a Streams or Observables or a while Loop or setState() or something else for such a boolean check. And I also don't know how to setup a solution.
This is my basic code for register a user:
import 'package:cloud_firestore/cloud_firestore.dart';
import 'dart:async';
class AuthService {
final FirebaseAuth _auth = FirebaseAuth.instance;
final Firestore _db = Firestore.instance;
Future<FirebaseUser> get getUser => _auth.currentUser();
Stream<FirebaseUser> get user => _auth.onAuthStateChanged;
Future<FirebaseUser> edubslogin(String email, String password) async {
try {
final FirebaseUser user = await _auth.createUserWithEmailAndPassword(
email: email,
password: password,
);
await user.sendEmailVerification();
//email verification somewhere here
updateUserData(user);
return user;
} catch (error) {
print(error);
return null;
}
}
I've tried this:
if (user.isEmailVerified == true) {
//go to Homescreen
return true;
} else {
//show verification screen(loading spinner)
return false;
}
But I don't get a boolean value true out of isEmailVerified.
What do I have to do?
I faced the same situation in my app. My solution was to create a periodic timer into the initState method of a strategic route to hold the app until the e-mail is verified. It is not so elegant as using a listener but works fine.
import 'dart:async';
import 'package:firebase_auth/firebase_auth.dart';
class _AccountConfirmationState extends State<AccountConfirmation> {
late Timer _timer;
#override
void initState() {
super.initState();
_timer = Timer.periodic(const Duration(seconds: 5), (timer) async {
await FirebaseAuth.instance.currentUser?.reload();
final user = FirebaseAuth.instance.currentUser;
if (user?.emailVerified ?? false) {
timer.cancel();
Navigator.pop(context, true);
}
});
}
#override
void dispose() {
super.dispose();
_timer.cancel();
}
#override
Widget build(BuildContext context) {
//TODO: Implement your amazing waiting screen here
}
}
This verification isn't as straightforward as you'd hope. First, there is the problem of recognizing that the user has verified their email. Second, there is the issue that there isn't any sort of a notification you can listen to that will automatically trigger a change in your app.
Check this thread for info about emailVerified: https://github.com/flutter/flutter/issues/20390#issuecomment-514411392
I was only able to verify the user if I 1) Created their account, 2) Signed them in, 3) Then checked to make sure they verified their email.
final FirebaseAuth _auth = FirebaseAuth.instance;
var _authenticatedUser = await _auth.signInWithEmailAndPassword(email: _email, password: _password);
//where _email and _password were simply what the user typed in the textfields.
if (_authenticatedUser.isEmailVerified) {
//Verified
} else {
//Not verified
}
Part 2: How do you get your app to recognize that the user has confirmed their email? Find a way to trigger the function that checks confirmation. A button would be easy enough. If you want it to see "automatic" then I guess you could create a timer that checks for email verification every 10 seconds or so.
Well I created a stream to handle this. Not so elegant but works. Use a StreamProvider.value() to handle events.
Stream<userVerificationStatus> checkUserVerified() async* {
bool verified = false;
yield userVerificationStatus(status: Status.LOADING);
while (!verified) {
await Future.delayed(Duration(seconds: 5));
FirebaseUser user = await _auth.currentUser();
if(user!=null)await user.reload();
if (user == null) {
yield userVerificationStatus(status: Status.NULL);
} else {
print("isemailverified ${user.isEmailVerified}");
await user.reload();
verified = user.isEmailVerified;
if(verified)
yield userVerificationStatus(status: Status.VERIFIED);
else
yield userVerificationStatus(status: Status.NOT_VERIFIED);
}
}
}
True. None of the FirebaseAuth idTokenChanges() , authStateChanges() or userChanges() will send you an event if the user verifies their email. I'm using a combination of the methods to get an email verification update in my app and it seems to be working well.
First I check the status in the initState() method and start a timer if email is not verified
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
//Get Authenticated user
user = context.read<AuthenticationService>().currentUser();
_isEmailVerified = user.emailVerified;
if (!_isEmailVerified) _startEmailVerificationTimer();
}
I also listen for app background/foreground events in case the user happens to leave the app to confirm their email ( If you also do this, add WidgetsBindingObserver to your class)
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
if (state == AppLifecycleState.resumed) {
user = context.read<AuthenticationService>().reloadCurrentUser();
if (user.emailVerified) {
setState(() {
_isEmailVerified = user.emailVerified;
});
timer?.cancel();
} else {
if (!timer.isActive) _startEmailVerificationTimer();
}
}
}
This is the _startEmailVerificationTimer() method
_startEmailVerificationTimer() {
timer = Timer.periodic(Duration(seconds: 5), (Timer _) {
user = context.read<AuthenticationService>().reloadCurrentUser();
if (user.emailVerified) {
setState(() {
_isEmailVerified = user.emailVerified;
});
timer.cancel();
}
});
}
Don't forget to dispose the timer
#override
void dispose() {
timer?.cancel();
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}
My Firebase User methods in case anyone is interested:
User currentUser() {
return _firebaseAuth.currentUser;
}
User reloadCurrentUser() {
User oldUser = _firebaseAuth.currentUser;
oldUser.reload();
User newUser = _firebaseAuth.currentUser;
return newUser;
}
In order for the app to recognise if the user has verified their email you can achieve this with a simple user.reload.
In order to test it yourself implement a button with onPressed code:
FlatButton(
child: Text("check"),
textColor: Colors.white,
onPressed: () async {
try {
FirebaseUser user = await _firebaseAuth.currentUser();
await user.reload();
user = await _firebaseAuth.currentUser();
print( user.isEmailVerified);
} catch (e) {
return e.message;
}
}),
I had the same problem with the latest version of firebase auth.
But I found out there is a function for reloading the current user which signed in
Future<bool> get userVerified async {
await FirebaseAuth.instance.currentUser.reload();
return FirebaseAuth.instance.currentUser.emailVerified;
}
referesh token after checking current user emailVerified is true
var user = FirebaseAuth.instance.currentUser;
await user?.reload();
if (user?.emailVerified == true) {
await FirebaseAuth.instance.currentUser?.getIdToken(true);
//rest code..
}
also please let me know if this a correct way of doing things.
I have found a way by updating firebase user profile and calling it in init() like below function.
void _checkEmailVerification() async {
await widget.auth.getCurrentUser().then((user) {
UserUpdateInfo userUpdateInfo = new UserUpdateInfo();
userUpdateInfo.displayName = user.displayName;
user.updateProfile(userUpdateInfo).then((onValue) {
setState(() {
_isEmailVerified = user.isEmailVerified;
});
});
});
}
Auth state change listener didn't work for me. Field isEmailVerified remains false even after user verifies his email.
My workaround:
Started from the assumption that user leaves the app to verify his email (which mean app is paused), and he returns to the app after verifying it (app resumes).
What I did was attach a WidgetsBinding to a relevant stateful widget where I wanted to display if email was verified (but can be done elsewhere). This involves two steps.
First step is to attach the binding:
#override
void initState() {
WidgetsBinding.instance.addObserver(this);
super.initState();
}
#override
void dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}
Second step is to override the didChangeAppLifecycleState to reload the user. I created a function that does the reload and sets a new firebaseUser object
void didChangeAppLifecycleState(AppLifecycleState state) {
if (state == AppLifecycleState.resumed && !firebaseUser.isEmailVerified)
refreshFirebaseUser().then((value) => setState(() {}));
super.didChangeAppLifecycleState(state);
}
Future<void> refreshFirebaseUser() async {
await firebaseUser.reload();
firebaseUser = FirebaseAuth.instance.currentUser;
}
So what this is basically doing is to reload firebase user object everytime the user returns to the app, while its email is not verified. I chose this solution over setting and cancelling a timer as it avoided setting a recurrent action through a timer which could be overkill for this particular problem.
Since authOnChanged only listens for sign in and sign out actions, in your sign in method, first sign out then try to sign in.
await _firebaseAuth.signOut();
authResult = await _firebaseAuth.signInWithEmailAndPassword(email: email, password: password);
return authResult.user;
In the onAuthChanged, when you control if user.isEmailVerified, it will work since you have signed out and it will update the user even if you haven't signed in yet because sign out will trigger your onAuthChanged even if you haven't signed in.
It is like cheating but the only way that I have found without timeout is this.