如何使用 Firebase 身份验证保持用户登录 Flutter web 应用程序

Question

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I am developing a FLutter web app and using Firebase Authentication with email and password login for signing in users

await FirebaseAuth.instance
      .signInWithEmailAndPassword(email: email, password: password);

After Successfully signing in, the code redirects the user to a HomePage.

        Navigator.of(context).pushReplacementNamed('/HomePage');

But when the user refreshes the web page or tries to go to the website again, it has signed out and has to log in again.

Following is the code I use to check the logged in user

StreamBuilder<User?>(
    stream: FirebaseAuth.instance.userChanges(),
    initialData:  FirebaseAuth.instance.currentUser,
    builder: (context, snapshot) {
      if (snapshot.connectionState == ConnectionState.done) {
        if (snapshot.data == null){
          Navigator.of(context).pushReplacementNamed('/HomePage');
        }else{
          Navigator.of(context).pushReplacementNamed('/signup');
        }
      }

How can I keep the user logged in as long as they use log out? I want the solution to work specifically on flutter web.

Answer 1

whatever you are building flutter app, web or desktop. you need to keep recorder of user in share preference. this package shared_preferences: ^2.0.15 support web app too. when user will logout then you must need to remove saved data. Click here:

Answer 2

You should navigate to signup when data is null and to home otherwise but you are doing it reverse.

builder: (context, snapshot) {
  if (snapshot.connectionState == ConnectionState.done) {
    if (snapshot.data == null){
      Navigator.of(context).pushReplacementNamed('/signup');
    }else{
      Navigator.of(context).pushReplacementNamed('/Homepage');
    }
  }