I am building a Flutter application and I have integrated Firebase, but I keep getting this error when I click on a button either to register, login or logout. I have seen other people have asked the same question, but none seems to work for me. I am using Flutter and Android Studio. How can I fix this problem?
This is an excerpt of my code
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.red,
body: Center(
child: Container(
child: RaisedButton(
onPressed: () {
FirebaseAuth.instance.signOut().then((value) {
Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (context) =>
LoginScreen()));
});
},
child: Text("Logout"),
)
)
)
);
}
}
Below is the thrown exception
══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
The following FirebaseException was thrown while handling a gesture:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()
When the exception was thrown, this was the stack:
#0 MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:118:5)
#1 Firebase.app (package:firebase_core/src/firebase.dart:52:41)
#2 FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3 _HomeScreenState.build.<anonymous closure> (package:cosytok/screens/home.dart:20:28)
#4 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:992:19)
#5 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:1098:38)
#6 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:184:24)
#7 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:524:11)
#8 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:284:5)
#9 BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:219:7)
#10 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:477:9)
#11 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:78:12)
#12 PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:124:9)
#13 _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:377:8)
#14 PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:122:18)
#15 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:108:7)
#16 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:220:19)
#17 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:200:22)
#18 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:158:7)
#19 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:104:7)
#20 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:88:7)
#24 _invoke1 (dart:ui/hooks.dart:267:10)
#25 _dispatchPointerDataPacket (dart:ui/hooks.dart:176:5)
(elided 3 frames from dart:async)
Handler: "onTap"
Recognizer:
TapGestureRecognizer#f0104
════════════════════════════════════════════════════════════════════════════════════════════════════
════════ Exception caught by gesture ═══════════════════════════════════════════════════════════════
The following FirebaseException was thrown while handling a gesture:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()
const app = initializeApp(firebaseConfig); A Firebase App is a container-like object that stores common configuration and shares authentication across Firebase services. After you initialize a Firebase App object in your code, you can add and start using Firebase services.
All Firebase versions have been updated and now you have to call Firebase.initializeApp()
before using any Firebase product, for example:
First, all Firebase products now depend on firebase_core
version (0.5.0+), therefore you need to add it in the pubspec.yaml
file:
dependencies:
flutter:
sdk: flutter
firebase_core : ^0.5.0
# cloud_firestore: ^0.14.0 other firebase dependencies
Then you have to call Firebase.initializeApp()
:
import 'package:flutter/material.dart';
// Import the firebase_core plugin
import 'package:firebase_core/firebase_core.dart';
void main() {
runApp(App());
}
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return FutureBuilder(
// Initialize FlutterFire
future: Firebase.initializeApp(),
builder: (context, snapshot) {
// Check for errors
if (snapshot.hasError) {
return SomethingWentWrong();
}
// Once complete, show your application
if (snapshot.connectionState == ConnectionState.done) {
return MyAwesomeApp();
}
// Otherwise, show something whilst waiting for initialization to complete
return Loading();
},
);
}
}
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: FirstRoute(title: 'First Route'),
);
}
}
class FirstRoute extends StatefulWidget {
FirstRoute({Key key, this.title}) : super(key: key);
final String title;
@override
_FirstRouteState createState() => _FirstRouteState();
}
class _FirstRouteState extends State<FirstRoute> {
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("test"),
),
body: FutureBuilder(
future: getData(),
builder: (context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
return Column(
children: [
Container(
height: 27,
child: Text(
"Name: ${snapshot.data.data()['name']}",
overflow: TextOverflow.fade,
style: TextStyle(fontSize: 20),
),
),
],
);
} else if (snapshot.connectionState == ConnectionState.none) {
return Text("No data");
}
return CircularProgressIndicator();
},
));
}
Future<DocumentSnapshot> getData() async {
await Firebase.initializeApp();
return await FirebaseFirestore.instance
.collection("users")
.doc("docID")
.get();
}
}
Initialize it in initState()
then call setState()
which will call the build()
method.
@override
void initState() {
super.initState();
Firebase.initializeApp().whenComplete(() {
print("completed");
setState(() {});
});
}
Initialize it in the main()
method after calling WidgetsFlutterBinding.ensureInitialized();
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
initializeApp()
onceAdd to pubspec.yaml
firebase_core :
add to main.dart
import 'package:firebase_core/firebase_core.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
If you followed Peter's answer and are still getting the same error, check to make sure anything else you have in your main
function comes after the await Firebase.initializeApp()
call, like so:
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
FirebaseCrashlytics.instance.setCrashlyticsCollectionEnabled(true);
FlutterError.onError = FirebaseCrashlytics.instance.recordFlutterError;
runApp(MyApp());
}
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