CODEWITHSUNDEEP
fluttergoogle-cloud-firestore
Mrunal Joshi
Mrunal Joshi

Reputation: 377

Future builder returning length as null

I am retreiving data from cloud firestore and using Future builder and Listview Builder to display the data. But i am getting null values in the Listview builder i.e displaying the CircularProgressIndicator always.Can't figure out the problem.Any solution will be of great help.

The print(values) function prints out: [9,8] successfully

This is the code i implemented:

Future<List> getassignment() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    final name = prefs.getString('orgname') ?? '';
    print(name);
    

      var query = FirebaseFirestore.instance.collection('Org').doc(name).collection('Login').doc(FirebaseAuth.instance.currentUser.uid);
    query.snapshots().forEach((doc) {

    List values = List.from(doc.data()['fields']['class']);
    print(values);
    return values;

    });

  }

  // void getlist() async{
  //   await getassignment();
  // }       

  @override
  void initState() {
    
    // getlist();
    super.initState();
  }

  

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Color(0xFF1976D2),
      body: FutureBuilder(
        future: getassignment(),
        builder: (context,snapshot){
          List list = snapshot.data;
          if (!snapshot.hasData) {
            return Center(child: CircularProgressIndicator());
         } else{
           return Container(
             child: ListView.builder(
          itemCount: snapshot.data.length,
          itemBuilder: (context, position) {
            return GestureDetector(
              onTap: (){
                Navigator.of(context).push(MaterialPageRoute<Null>(
                                      builder: (BuildContext context){
                                        return new SubjectList(
                                          clas: list[position].toString(),
                                        );
                                      }
                                      ));
              },
              child: Card(
                
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Text(list[position].toString(), style: TextStyle(fontSize: 22.0),),
                  
                ),
              ),
            );
          },
        ),
           );
         }
        },
              
      ),
    );
  }

Upvotes: 0

Views: 194

Answers (1)

Amit Jangid
Amit Jangid

Reputation: 2889

You are assigning and returning data inside of foreach loop. So that won't return anything.

// try adding await in this line.
var query = await FirebaseFirestore.instance.collection('Org').doc(name).collection('Login').doc(FirebaseAuth.instance.currentUser.uid);

List values = query.snapshots().forEach((doc) => List.from(doc.data()['fields']['class']));

print(values);
return values;

You need to do something like this.

Upvotes: 1

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