Can we use 'Firestore' like this? - firebase

Question

I downloaded flutter chat app on Github and I was learning through it. The original developer used Firestore but in mine, I am getting an error "Undefined name 'Firestore'.
Try correcting the name to one that is defined, or defining the name" like this.
I search for this and I read in cloudfirestore docs we can use "FirebaseFirestore" (maybe I am wrong). I am learning to write backend with flutter and so far I did UI parts. so this is my first attempt at learning backend with flutter.
handleSignIn() async {
final res = await googleSignIn.signIn();
SharedPreferences sharedPreferences = await SharedPreferences.getInstance();
final auth = await res.authentication;
final credentials = GoogleAuthProvider.getCredential(
idToken: auth.idToken, accessToken: auth.accessToken);
final firebaseUser =
(await firebaseAuth.signInWithCredential(credentials)).user;
if (firebaseUser != null) {
final result = (await Firestore.instance
.collection('users')
.where('id', isEqualTo: firebaseUser.uid)
.getDocuments())
.documents;
if (result.length == 0) {
///new user
Firestore.instance
.collection('users')
.document(firebaseUser.uid)
.setData({
"id": firebaseUser.uid,
"name": firebaseUser.displayName,
"profile_pic": firebaseUser.photoURL,
"created_at": DateTime.now().millisecondsSinceEpoch,
});
sharedPreferences.setString("id", firebaseUser.uid);
sharedPreferences.setString("name", firebaseUser.displayName);
sharedPreferences.setString("profile_pic", firebaseUser.photoURL);
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => Home()));
} else {
///Old user
sharedPreferences.setString("id", result[0]["id"]);
sharedPreferences.setString("name", result[0]["name"]);
sharedPreferences.setString("profile_pic", result[0]["profile_pic"]);
Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => Home()));
}
}
}
this is the error I'm getting
so can you guys explain how to solve this error?
Thank You.

Answer 1

I think you are missing to add cloud_firestore dependency in pubspec.yml. One more thing,
you are using latest version, use "FirebaseFirestore" instead of "Firestore".

Answer 2

Go to pubspec.yaml file in your flutter project.
Add this( cloud_firestore: ^0.16.0 ) below dependencies like in the image below.
You can skip this step if you use VScode. It does this automatically if you save the file after the update.
IF NOT , do flutter pub get inside your project. (this fetches the new packages added to the project, in our case cloud_firestore)
Make sure that you are able to see this import in the file you are getting the errors in.
import 'package:cloud_firestore/cloud_firestore.dart';
Next, update Firestore.instance -> FirebaseFirestore.instance in all your files where you are getting this error.

Answer 3

Use this code --
FirebaseFirestore.instance
.collection("users").add({"name": "Majeed"});
change Firestore with FirebaseFirestore and remove the Document and setData
replace setData with add.