CODEWITHSUNDEEP
firebaseflutterdartgoogle-cloud-firestore
ro br
ro br

Reputation: 250

How do I get data from Firebase using FlutterFire Firestore and Flutter 2.0 with Null Safety

I'm getting the error on the code "snapshot.Data()". This is one of the breaking changes to Firestore, and snapshot is now of type "DocumentSnapshot<Object?>".

BREAKING: Getting a snapshots' data via the data getter is now done via the data() method.

The example supplied in the new documentation wasn't helpful for me.

"The argument type 'Object?' can't be assigned to the parameter type 'Map<String, dynamic>'"

I've tried a number of combinations, but I can't get rid of the error. Also, I'm not using a stream, I just want to read the single record.

Here is the code:

var snapshot = await _reference.doc(_user.uid).get();
return UserData.fromMap(snapshot.data());

Here is the model "fromMap":

factory UserData.fromMap(Map<String, dynamic> map) {
    return UserData(
      birthday: DateTime.fromMillisecondsSinceEpoch(map['birthday']),
      gender: map['gender'],
      isDarkMode: map['isDarkMode'],
      isMetric: map['isMetric'],
      name: map['name'],
      password: map['password'],
    );
  }

Upvotes: 1

Views: 1547

Answers (2)

ro br
ro br

Reputation: 250

Ok, found my issue. I had "_reference" defined like this:

final  CollectionReference _reference = FirebaseFirestore.instance.collection('users');

I should have done it this way:

final  CollectionReference<Map<String, dynamic>> _reference = FirebaseFirestore.instance.collection('users');

Or just this:

  final _reference = FirebaseFirestore.instance.collection('users');

Upvotes: 2

Huthaifa Muayyad
Huthaifa Muayyad

Reputation: 12353

Change it to this:

factory UserData.fromMap(Map<String, dynamic>? map) //added a "?" after dynamic.

This makes your fromMap method accept nullable values, which in theory, your firebase query can return a null if the document doesn't exist.

Upvotes: 1

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