I have created an Homepage and from that user can sign in for the app and in the next screen user can see their profile info(Only profile name) and under that their is signOut button. User can signOut from the app using signOut button.But it's not working for me.
I want to call signOut method from main.dart by pressing signOut button in details.dart(both the classes are in different file)
But when i press signOut Button in details.dart nothing happens!
And code is given below:
main.dart
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'details.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
theme: new ThemeData(
primarySwatch: Colors.blue,
),
debugShowCheckedModeBanner: false,
home: new MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
MyHomePageState createState() => MyHomePageState();
}
class MyHomePageState extends State<MyHomePage> {
final FirebaseAuth firebaseAuth = FirebaseAuth.instance;
final GoogleSignIn googleSignIn = GoogleSignIn();
static bool _LoginButton = true;
void signOut(){
googleSignIn.signOut();
setState((){
_LoginButton = true;
});
print(_LoginButton);
print("User Signed Out");
}
Future<FirebaseUser> _signIn() async{
if(_LoginButton==true){
setState((){
_LoginButton=false;
});
GoogleSignInAccount googleSignInAccount = await googleSignIn.signIn();
GoogleSignInAuthentication googleSignInAuthentication = await googleSignInAccount.authentication;
FirebaseUser firebaseUser = await firebaseAuth.signInWithGoogle(idToken: googleSignInAuthentication.idToken, accessToken: googleSignInAuthentication.accessToken);
print("Username is "+firebaseUser.displayName);
setState((){
_LoginButton = true;
});
Navigator.push(context, MaterialPageRoute(builder: (context) => details(firebaseUser.displayName,signOut)));
return firebaseUser;
}
}
bool _LoginButtonBool(){
return _LoginButton;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("Google auth with firebase"),),
body: Center(
child: _LoginButtonBool()?Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
MaterialButton(onPressed: _LoginButtonBool() ? () => _signIn().then((FirebaseUser firebaseuser ) =>print(firebaseuser)).catchError((e) => print(e)): null,
child: Text("Login"),color: Colors.orange,),
],
),
):CircularProgressIndicator(backgroundColor: Colors.greenAccent.withOpacity(0.01),),
),
);
}
}
details.dart
import 'package:flutter/material.dart';
import 'package:flutter_auth/main.dart';
class details extends StatelessWidget {
String name;
final Function callback;
details(this.name,this.callback);
@override
Widget build(BuildContext context) {
return Scaffold(
body:Center(child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Text(name),
MaterialButton(onPressed: () => callback,
child: Text("Log out"),color: Colors.orange),
],
),),
);
}
}
We can access it easily just like below. Show activity on this post. Show activity on this post. Import HomePage class in DetailsPage and make a new instance out of it, then call the method you want if it's a public one.
In Flutter this can be done using a stateful widget and calling your code in the initState function. What if you want to call it from a stateless widget? Well, that's possible too. Use a stateful widget as a your root widget that you can provide a callback function too to execute your startup logic.
Use GlobalKey With the help of GlobalKey, we can access the State of Flutter widgets hence allowing us to call methods from any child widget. Now in order to use GlobalKey we need to make a few changes in our code. Firstly, we need to add a Key identifier to our MyWidget constructor.
It is simple let me explain with an example
class Animals
{
var animalList = ['dog','cat','cow'];
// function for printing the list of animals
void animalListPrinter(){
for(var animal in animalList){
print(animal);
}
}
}
Calling the above function to another class
class ShowingAnimalList extends StatelessWidget {
final Animals ani= new Animals();
@override
Widget build(BuildContext context) {
return GestureDetector(
onTap:()=> ani.animalListPrinter(),
);
}
}
You can call any Widget with this from the parent class
You must be careful with what you are trying to do because you might be accessing a page/widget that is not mounted. Imagine you do a pushReplacement(new MaterialPageroute(...))
. The previous page is no longer available in the tree so you can't access it nor any of its methods.
Unless you have a clear parent child relationship in your tree, you should abstract away your logic to external or business logic classes. Thus you are sure that you are calling active instances of your classes.
Here is an example of what you could use passing around the Business object. It would be even better if you use other patterns like BLOC, ScopedModel, Streams, etc. But for the sake of simplicity I think this should be enough.
import "package:flutter/material.dart";
void main() {
runApp(MyApp(new Logic()));
}
class Logic {
void doSomething() {
print("doing something");
}
}
class MyApp extends StatelessWidget {
final Logic logic;
MyApp(this.logic);
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new HomePage(widget.logic),
);
}
}
class HomePage extends StatelessWidget {
final Logic logic;
HomePage(this.logic);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: FlatButton(
onPressed: () { Navigator.of(context).pushReplacement(
MaterialPageRoute(
builder: (context) => AnotherPage(logic),
))},
child: Text("Go to AnotherPage"),
),
),
);
}
}
class AnotherPage extends StatelessWidget {
final Logic logic;
AnotherPage(this.logic);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: FlatButton(
onPressed: logic.doSomething,
child: Text("Press me"),
),
),
);
}
}
If you still want to call a function in the other Page and you are sure the page is mounted (you have done a push
instead of a pushReplacement
) you could do the following. (handle with care)
class HomePage extends StatelessWidget {
HomePage();
void onCalledFromOutside() {
print("Call from outside");
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: FlatButton(
onPressed: () { Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => AnotherPage(onCalledFromOutside),
))},
child: Text("Go to AnotherPage"),
),
),
);
}
}
class AnotherPage extends StatelessWidget {
final Function callback
AnotherPage(this.callback);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: FlatButton(
onPressed: callback,
child: Text("Press me"),
),
),
);
}
}
We can access it easily just like below.
className().MethodName(),
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