how to handle firebase auth exceptions in flutter?

Question

i have developed a login page.but i don't know how to catch firebase auth exceptions on flutter and display them.i want to display something email doesn't exist, password didn't match.

Here's my code:

Future<void> login() async{
    final  formState = _formkey.currentState;
    if(formState.validate()){
      formState.save();
      try{

        final FirebaseUser user = (await FirebaseAuth.instance.signInWithEmailAndPassword(email: _username, password: _password)).user;

          Navigator.push(context, MaterialPageRoute(builder: (context) => Admin()));
      }catch(e){
        print(e.message);
      }

Can someone help me finding a way to validate the login please.

Peter Haddad Peter Haddad · Accepted Answer · 2019-12-13T18:46:52

You can use a Toast to display the error:

# add this line to your dependencies
toast: ^0.1.5

Then in the dart file import it:

import 'package:toast/toast.dart';

Then inside the catch:

 }catch(e){
        print(e.message);
    Toast.show(e.message, context, duration: Toast.LENGTH_SHORT, gravity:  Toast.BOTTOM);    
 }

https://pub.dev/packages/toast

You don't have to check if the email is wrong or not, the signInWithEmailAndPassword already does that for you and will return an error if the authentication was wrong.

how to handle firebase auth exceptions in flutter?

2 Answers