Firebase authentication error: Undefined name 'auth'

Question

I would like to acces my firestore databse, by using the UID of each user, like so:

return new StreamBuilder(
    stream: Firestore.instance.collection('users').document(uid).snapshots(),
    builder: (context, snapshot) {
      if (!snapshot.hasData) {
        return new Text("Loading");
      }
      var userDocument = snapshot.data;

And for getting the UID:

final FirebaseUser user = auth.currentUser().then((FirebaseUser user) {
  final userid = user.uid;
});

This but I keep getting the error

Undefined name 'auth'.

Answer 1

To use FirebaseAuth in flutter, you must get a reference to such instance. Add this line at the top of your widget/file whenever you need to use Firebase Authentication:

import 'package:firebase_auth/firebase_auth.dart';

FirebaseAuth auth = FirebaseAuth.instance;

Now you can use stuff like auth.currentUser().then(...) like you are doing correctly.

Answer 2

Undefined name 'FirebaseAuth', and not importing library firebase_auth