This is the firebase database structure that I am using:

import 'package:awesome_dropdown/awesome_dropdown.dart';
import 'package:carousel_slider/carousel_controller.dart';
import 'package:carousel_slider/carousel_slider.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:hexated/Refactored/widgets/headings.dart';
import 'package:smooth_page_indicator/smooth_page_indicator.dart';

import '../Refactored/sections/bottomNavigation.dart';
import '../Refactored/sections/todaysMealContainer.dart';
import '../Refactored/widgets/mealDayList.dart';

class messDiary extends StatefulWidget {
  messDiary({Key? key}) : super(key: key) {}

  // late String whatIsToday = DateFormat('EEEE').format(DateTime.now());

  @override
  State<messDiary> createState() => _messDiaryState();
}

class _messDiaryState extends State<messDiary> {
  int activeIndex = 0;
  final carouselController = CarouselController();
  String valueChoose = 'Select a day';
  var itemName;

  final CollectionReference _collectData =
      FirebaseFirestore.instance.collection('messdiary');
  late Stream<QuerySnapshot> _streamCollect;

  @override
  void initState() {
    super.initState();
    _streamCollect = _collectData.snapshots();
  }

  @override
  Widget build(BuildContext context) {
    double height = MediaQuery.of(context).size.height;
    double width = MediaQuery.of(context).size.width;
   
    return Scaffold(
      backgroundColor: const Color(0xFF000000),
      appBar: AppBar(
        backgroundColor: const Color(0xFF000000),
        elevation: 0,
      ),
      bottomNavigationBar: const bottomNavigation(),
      body: ListView(
        children: [
          Column(
            children: [
              headings(headingText: "Today's meals"),
              const SizedBox(
                height: 15,
              ),
              StreamBuilder<QuerySnapshot>(
                  stream: _streamCollect,
                  builder: (context, AsyncSnapshot<QuerySnapshot> snapshot) {
                    if (!snapshot.hasData) {
                      return const Center(
                        child: CircularProgressIndicator(),
                      );
                    }
                    List<DocumentSnapshot> snaps = snapshot.data!.docs;
                    return CarouselSlider(
                      options: CarouselOptions(
                        height: height * 0.38,
                        aspectRatio: 2.0,
                        autoPlayCurve: Curves.easeInOutQuart,
                        pauseAutoPlayOnTouch: true,
                        enlargeCenterPage: true,
                        enableInfiniteScroll: false,
                        initialPage: 2,
                        autoPlay: true,
                        onPageChanged: (index, reason) {
                          setState(() {
                            activeIndex = index;
                          });
                        },
                      ),
                      items: snaps.map((e) {
                        return Builder(builder: (BuildContext context) {
                          return todaysMeal(
                              itemName: e['title'],
                              itemImage: e['image'],
                              time: e['time'],
                              dayTime: e['daytime']);
                        });
                      }).toList(),
                    );
                  }),
              const SizedBox(
                height: 15,
              ),
              AnimatedSmoothIndicator(
                onDotClicked: animateToSlide,
                effect: const ExpandingDotsEffect(
                    dotWidth: 14,
                    dotHeight: 14,
                    activeDotColor: Color(0xFF6A7086),
                    dotColor: Color(0xFF2B2E3F)),
                activeIndex: activeIndex,
                count: 4,
              ),
       
        ],
      ),
    );
  }

}

When i try to run the code this error message appears

======== Exception caught by widgets library ======================================================= The following StateError was thrown building Builder(dirty):

Bad state: field does not exist within the DocumentSnapshotPlatform

If it is not the way to access the data then how??

i have tried to the end and tired please help me to fix this issue!!

CodePudding user response：

The field names are 'sunday', 'monday', and so on. Each of these fields has an array of [todaysMeal] jsons, in a manner of speaking.

What you are trying to access are the fields inside each array element.

So what's happening is: you are looking for json keys 'title', 'image', 'daytime', and 'time', but the document snapshot has these keys: 'sunday', 'monday', etc.

I don't think I worded this answer very well, but I hope this was enough to clear up your confusion.

I am replying to your comments here. Here are the code changes that you can try.

// First of all change the don't use the CollectionReference for 'messdiary'.
// final CollectionReference _collectData = FirebaseFirestore.instance.collection('messdiary');
// Use the DocumentReference for 'days'.
final DocumentReference _daysData =
  FirebaseFirestore.instance.collection('messdiary').doc('days');

Then:-

// Change the following statement.
// List<DocumentSnapshot> snaps = snapshot.data!.docs;
// to this:
final daysObj = snapshot.data()!;
final sundayMeals = daysObj["sunday"]
  .map((e)=>todaysMeal(itemName: e['title'], itemImage: e['image'], time: e['time'], dayTime: e['daytime']))
  .toList();
final mondayMeals = ...
...
final saturdayMeals = ...
final mealsData = [...sundayMeals, ...mondayMeals, ....... , ...saturdayMeals];
// Now use mealsData for your carousel.

This code might not work entirely as you expected. You have to do any further debugging.

And if you need further help, I might have to charge you