Question 108560 in Flutter Question posted in
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Unable to display data when component loads in flutter

I am having an issue displaying data from a API call.

the data is there because when I do hot reload the component works perfect.

here is the parent component::


class _ReportsState extends State<Reports> {
  late DiaryFirebaseCloudStorage _diaryRepository;
  late var _createdDiariesInThePast30Days;

  @override
  void initState() {
    super.initState();
    _diaryRepository = DiaryFirebaseCloudStorage();
    setVariables();
  }

  setVariables() async {
    _createdDiariesInThePast30Days =
        await _diaryRepository.getCreatedDiariesBasedOnPreviousDays(30);
  }

  @override
  Widget build(BuildContext context) {
    
    return Scaffold(
        appBar: PreferredSize(
          preferredSize: Size.fromHeight(kToolbarHeight),
          child: AppBarIconContainer(),
        ),
        body: Column(children: [
          Expanded(
              child: GridView.count(
                  crossAxisCount: 2, // Number of boxes per row
                  children: [
                SingleDigitReport(
                    number: _createdDiariesInThePast30Days.toString())
              ]))
        ]));
  }
}

this is the class being used to get the data from firebase:::


class DiaryFirebaseCloudStorage {
  final _diary = FirebaseFirestore.instance.collection('diary');
  // final _user = FirebaseAuth.instance.currentUser!;
  final _user = AuthHandler.getUser();

  // Future<int>
  getCreatedDiariesBasedOnPreviousDays(days) async {
    print("getCreatedDiariesBasedOnPreviousDays()");
    final now = DateTime.now();
    final daysDelta = now.subtract(Duration(days: days));
    final querySnapshot = await _diary
        .where(createdByColumn, isEqualTo: _user.uid)
        .where(createdOnColumn, isGreaterThan: daysDelta)
        .get();
    return querySnapshot.docs.length;
  }

// singleton
  static final DiaryFirebaseCloudStorage _shared =
      DiaryFirebaseCloudStorage._sharedInstance();
  DiaryFirebaseCloudStorage._sharedInstance();
  factory DiaryFirebaseCloudStorage() => _shared;
}

what am I doing wrong?

here is a video of the issue::
https://youtu.be/lAqI7rwP-bE

this is the error:::

════════ Exception caught by widgets library ═══════════════════════════════════
The following LateError was thrown building Reports(dirty, state: _ReportsState#8004c):
LateInitializationError: Field '_createdDiariesInThePast30Days@561088100' has not been initialized.

The relevant error-causing widget was
Reports
hub.dart:70
When the exception was thrown, this was the stack
#0      _ReportsState._createdDiariesInThePast30Days (package:thraive/pages/reports/reports.dart)
reports.dart:1
#1      _ReportsState.build
reports.dart:46
#2      StatefulElement.build
framework.dart:5080
#3      ComponentElement.performRebuild
framework.dart:4968
#4      StatefulElement.performRebuild

I asked chatgpt and looked at other StackOverflow posts and I cant find anything!

Tags:

2

Answers


  1. 0

    Instead of this

    late DiaryFirebaseCloudStorage _diaryRepository;
late var _createdDiariesInThePast30Days;

    Use this

    DiaryFirebaseCloudStorage? _diaryRepository;
var _createdDiariesInThePast30Days;
    Login or Signup to reply.
  2. 0

    You have declared variables as late however you didn’t initialize them before the build function started execution. Instead, convert all your late variables to nullable types.

    // From 
late var _createdDiariesInThePast30Days;

// To

// Because your function returns Future<int> change it to nullable int (int?)
int? _createdDiariesInThePast30Days;

// Or pre-initialize it with some value like 0
int _createdDiariesInThePast30Days = 0;

    This should resolve your issue, let me know if you are still facing issues.

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