I'm getting an error in a FutureBuilder while trying to retrieve data from the Firestore database.  The error message is:

The following StateError was thrown building FutureBuilder<DocumentSnapshot<Object?>>(dirty, state: _FutureBuilderState<DocumentSnapshot<Object?>>#9feea): Bad state: field does not exist within the DocumentSnapshotPlatform

The relevant error-causing widget was:   FutureBuilder<DocumentSnapshot<Object?>> FutureBuilder:file:///Users/cy/AndroidStudioProjects/improve_practice_app/lib/app/community/tabs/profile_tab.dart:47:24

I reviewed different SO threads and and still have no idea what to do to fix my code.  Firebase is definitely working properly and I don't see any missing fields.  Any help will be appreciated.  Thanks.

class ProfileTab extends StatefulWidget {
  const ProfileTab({
    Key? key,
  }) : super(key: key);

  @override
  State<ProfileTab> createState() => _ProfileTabState();
}

class _ProfileTabState extends State<ProfileTab> {
  final currentUser = Auth().currentUser?.uid;

  @override
  Widget build(BuildContext context) {
    return SafeArea(
        child: CustomScrollView(slivers: <Widget>[
      SliverToBoxAdapter(
          child: FutureBuilder<DocumentSnapshot<Map<String, dynamic>>>(
              future: Auth().usersReference.doc(currentUser).get(),
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return const AdaptiveCircularProgress();
                }
                AppUser appUser = AppUser.fromDocument(snapshot.data);
                return UserProfileHeaderContainer(headerContent: []);
              }))
    ]));
  }
}

class AppUser {
  AppUser({
    this.bio,
    this.displayName,
    this.followers,
    this.following,
    this.photoUrl,
    this.userID,
    this.userCart,
    this.userName,
  });

  final String? bio;
  final String? displayName;
  final List? followers;
  final List? following;
  final String? photoUrl;
  final List? userCart;
  final String? userID;
  final String? userName;

  factory AppUser.fromDocument(DocumentSnapshot? doc) {
    return AppUser(
      bio: doc?[FirebaseString.bio],
      displayName: doc?[FirebaseString.displayName],
      followers: doc?[FirebaseString.followers],
      following: doc?[FirebaseString.following],
      photoUrl: doc?[FirebaseString.photoUrl],
      userCart: doc?[FirebaseString.userCart],
      userID: doc?[FirebaseString.userID],
      userName: doc?[FirebaseString.userName],
    );
  }

  Map<String, dynamic> toJson() => {
    FirebaseString.bio: bio,
    FirebaseString.displayName: displayName,
    FirebaseString.followers: followers,
    FirebaseString.following: following,
    FirebaseString.photoUrl: photoUrl,
    FirebaseString.uid: userID,
    FirebaseString.userCart: userCart,
    FirebaseString.userName: userName,
  };
  
}

CodePudding user response：

You are parsing it wrong. You need to do something like.

factory AppUser.fromDocument(DocumentSnapshot<Map<String, dynamic>> doc) {

// it's the data map which has all the info
final map = doc.data()

return AppUser(
  bio: map[FirebaseString.bio],
  ....,
  ....,
  );
}