[📚] Example code does not work

[lukehutch]

Using the latest Flutter release, I tried the example code here:

https://pub.dev/packages/firebase_ui_auth

I get the following errors:

lib/main.dart:8:24: Error: 'EmailAuthProvider' is imported from both 'package:firebase_auth_platform_interface/src/providers/email_auth.dart' and 'package:firebase_ui_auth/src/providers/email_auth_provider.dart'.
    const providers = [EmailAuthProvider()];
                       ^^^^^^^^^^^^^^^^^
lib/main.dart:15:24: Error: The argument type 'List<dynamic>' can't be assigned to the parameter type 'List<AuthProvider<AuthListener, AuthCredential>>?'.
 - 'List' is from 'dart:core'.
 - 'AuthProvider' is from 'package:firebase_ui_auth/src/providers/auth_provider.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_ui_auth-1.1.2/lib/src/providers/auth_provider.dart').
 - 'AuthListener' is from 'package:firebase_ui_auth/src/providers/auth_provider.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_ui_auth-1.1.2/lib/src/providers/auth_provider.dart').
 - 'AuthCredential' is from 'package:firebase_auth_platform_interface/src/auth_credential.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_auth_platform_interface-6.11.4/lib/src/auth_credential.dart').
            providers: providers,
                       ^
lib/main.dart:25:24: Error: The argument type 'List<dynamic>' can't be assigned to the parameter type 'List<AuthProvider<AuthListener, AuthCredential>>?'.
 - 'List' is from 'dart:core'.
 - 'AuthProvider' is from 'package:firebase_ui_auth/src/providers/auth_provider.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_ui_auth-1.1.2/lib/src/providers/auth_provider.dart').
 - 'AuthListener' is from 'package:firebase_ui_auth/src/providers/auth_provider.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_ui_auth-1.1.2/lib/src/providers/auth_provider.dart').
 - 'AuthCredential' is from 'package:firebase_auth_platform_interface/src/auth_credential.dart' ('/opt/flutter/.pub-cache/hosted/pub.dartlang.org/firebase_auth_platform_interface-6.11.4/lib/src/auth_credential.dart').
            providers: providers,
                       ^

[lukehutch]

Commenting out

//import 'package:firebase_ui_auth/firebase_ui_auth.dart';

I get different errors, that

Abstract classes can't be instantiated.
Try creating an instance of a concrete subtype.dart[instantiate_abstract_class](https://dart.dev/diagnostics/instantiate_abstract_class)
The constructor being called isn't a const constructor.
Try removing 'const' from the constructor invocation.dart[const_with_non_const](https://dart.dev/diagnostics/const_with_non_const)
The values in a const list literal must be constants.
Try removing the keyword 'const' from the list literal.dart[non_constant_list_element](https://dart.dev/diagnostics/non_constant_list_element)
Const variables must be initialized with a constant value.
Try changing the initializer to be a constant expression.dart[const_initialized_with_non_constant_value](https://dart.dev/diagnostics/const_initialized_with_non_constant_value)

So it seems that the definition of EmailAuthProvider that is accessible via package:firebase_auth/firebase_auth.dart is an abstract class.

[lukehutch]

The correct working code seems to be:

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart' as fba;     // CHANGE: "as fba"
import 'package:firebase_ui_auth/firebase_ui_auth.dart';

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var providers = [EmailAuthProvider()];

    return MaterialApp(
      initialRoute: fba.FirebaseAuth.instance.currentUser == null ? '/sign-in' : '/profile',    // CHANGE: "fba."
      routes: {
        '/sign-in': (context) {
          return SignInScreen(
            providers: providers,
            actions: [
              AuthStateChangeAction<SignedIn>((context, state) {
                Navigator.pushReplacementNamed(context, '/profile');
              }),
            ],
          );
        },
        '/profile': (context) {
          return ProfileScreen(
            providers: providers,
            actions: [
              SignedOutAction((context) {
                Navigator.pushReplacementNamed(context, '/sign-in');
              }),
            ],
          );
        },
      },
    );
  }
}

[dhust]

GoogleProvider() and GoogleAuthProvider() don't work. Is there a solution to that? EmailAuthProvider works fine.

It states that The element type 'GoogleAuthProvider' can't be assigned to the list type 'AuthProvider<AuthListener, AuthCredential>'

[lukehutch]

With the changes I suggested, everything works for me.

[dhust]

I'm not seeing where you enabled signing in with Google. I'm only seeing EmailAuthProvider() in your code.

[lukehutch]

Oh, sorry, I didn't read your comment closely enough. I haven't enabled Google auth yet. I'll see what I can figure out.

[lukehutch]

@dhust I tried following the directions on this page, but I couldn't figure it out either:

https://github.com/firebase/flutterfire/blob/master/packages/firebase_ui_auth/doc/providers/oauth.md

I think I'm going to give up on FlutterFire at this point (the username/password login support is also buggy)...

[lesnitsky]

you need to use EmailAuthProvider from firebase_ui_auth.
there is a name conflict between EmailAuthProvider from firebase_auth and firebase_ui_auth
you should either use firebase_auth with an alias or hide EmailAuthProvider:

import 'package:firebase_auth/firebase_auth.dart' hide EmalAuthProvider;

or

import 'package:firebase_auth/firebase_auth.dart' as fba;

[dhust]

Do you know if the same is true with Google Sign In? It doesn't even recognize GoogleProvider or GoogleAuthProvider as a legitimate option. It only recognizes email and phone.