How to get user id from Firebase Auth in Flutter?

Question

I want to save user-related data in Firestore by assigning user id to a document as a field.

How to get user id from Firebase Auth?

Or is there a better way to store user data in Firestore?

I couldn't get user id from Firebase Auth in this way (the Text(_userId) returns _userId == null error):

String _userId;
  ...

  @override
  Widget build(BuildContext context) {
    FirebaseAuth.instance.currentUser().then((user) {
      _userId = user.uid;
    });

    return new Scaffold(
      appBar: new AppBar(
        title: new Text("App bar"),
      ),
      body: new Text(_userId),
    );
  }

Herohtar · Accepted Answer · 2019-02-11 21:30:37Z

21

_userId is null because the widgets are being built before the Future returned by FirebaseAuth.instance.currentUser() has completed. Once it does complete it's too late and the widgets don't update. One way to work with it would be to use a FutureBuilder somewhat like this:

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text("App bar"),
    ),
    body: FutureBuilder(
      future: FirebaseAuth.instance.currentUser(),
      builder: (context, AsyncSnapshot<FirebaseUser> snapshot) {
        if (snapshot.hasData) {
          return Text(snapshot.data.uid);
        }
        else {
          return Text('Loading...');
        }
      },
    ),
  );
}

edited Feb 11, 2019 at 21:30

answered Apr 14, 2018 at 7:16

Herohtar

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Comments

krishnaacharyaa · Accepted Answer · 2023-01-17 20:28:18Z

0

Current User Id:

  FirebaseAuth.instance.currentUser?.uid

To store user details in the `uid`:

Use set() method:

final user = <String, String>{
  "name": "Mohan Roy",
  "state": "CA",
  "country": "USA"
};

Firestore.instance
    .collection("users")
    .doc(FirebaseAuth.instance.currentUser!.uid)
    .set(user)
    .onError((e, _) => print("Error writing document: $e"));

Extra:

Current User Name:

  FirebaseAuth.instance.currentUser?.displayName

Current User Email:

  FirebaseAuth.instance.currentUser?.email

Current User Phone Number:

  FirebaseAuth.instance.currentUser?.phoneNumber

edited Jan 17, 2023 at 20:28

answered Jan 17, 2023 at 18:07

krishnaacharyaa

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How to get user id from Firebase Auth in Flutter?

2 Answers 2

Comments

Current User Id:

To store user details in the `uid`:

Extra:

Current User Name:

Current User Email:

Current User Phone Number:

Comments

Your Answer

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2 Answers 2

Comments

Current User Id:

To store user details in the uid:

Extra:

Current User Name:

Current User Email:

Current User Phone Number:

Comments

Your Answer

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To store user details in the `uid`: