Example of Firebase Auth with Email and Password on Flutter? - firebase

Question

First time implementing Firebase Auth, also new to Flutter dev, and I'm looking to use email and passwords, not Google sign-in. The only examples I see of Firebase Auth being used are anonymously or with Google. Is there a resource / tutorial that shows how to properly set up the calls with the signInWithEmailAndPassword method?
Many thanks!

Answer 1

In my app I have an auth class because I don't like to litter my widget classes with non-widget code, but you can plop this code inside your widget class if you want.
In auth.dart I have:
import 'package:firebase_auth/firebase_auth.dart';
class Auth {
final FirebaseAuth auth = FirebaseAuth.instance;
Future<User> handleSignInEmail(String email, String password) async {
UserCredential result =
await auth.signInWithEmailAndPassword(email: email, password: password);
final User user = result.user!;
return user;
}
Future<User> handleSignUp(email, password) async {
UserCredential result = await auth.createUserWithEmailAndPassword(
email: email, password: password);
final User user = result.user!;
return user;
}
}
Then in my login/register screen I create an instance of my auth class:
var authHandler = new Auth();
Finally, in my login buttons onPressed callback I have:
onPressed: () {
authHandler.handleSignInEmail(emailController.text, passwordController.text)
.then((FirebaseUser user) {
Navigator.push(context, new MaterialPageRoute(builder: (context) => new HomePage()));
}).catchError((e) => print(e));
}

Answer 2

Here is one example from my service. I ask for the email, name and password fields.
registerWithEmail(String name, String email, String password) async {
First I check if the email is already registered with facebook or something.
List<String> providers = await firebaseAuth.fetchProvidersForEmail(email: email);
This is not ideal solution, but you want to handle if the user is already registered, and than link email with current user
if (providers != null && providers.length > 0) {
print("already has providers: ${providers.toString()}");
return handleProviders(providers);
}
Create new User
FirebaseUser newUser = await firebaseAuth.createUserWithEmailAndPassword(email: email, password: password);
await newUser.sendEmailVerification();
This is basically it. I update the name filed of the user, since I have it.
var userUpdateInfo = new UserUpdateInfo();
userUpdateInfo.displayName = name;
await firebaseAuth.updateProfile(userUpdateInfo);
await newUser.reload();
And later You can save the user inside your firestore, where user uid is document ID. So I can get it later.

Answer 3

Git repo with full explanation example for Email/Password Sign in Firebase using flutter
This may help you.
Git Repo: https://github.com/myvsparth/firebase_email_signin
Full Article Step by Step: https://www.c-sharpcorner.com/article/how-to-do-simple-login-with-email-id-in-flutter-using-google-firebase/

Answer 4

This code is for register new user
fb_auth.UserCredential userCredential = await fb_auth
.FirebaseAuth.instance
.createUserWithEmailAndPassword(email: email, password: password);
And this is for login previous user
fb_auth.UserCredential userCredential = await fb_auth
.FirebaseAuth.instance
.signInWithEmailAndPassword(email: email, password: password)
And that fb_auth is
import 'package:firebase_auth/firebase_auth.dart' as fb_auth;