Adding data to existing list from initState in Flutter (Async)

Question

I try to load specific data from my Sembast database to the view on init and add it to an existing list. Why this code does not work?

The data exists, but could it be that my code will never called? I´ve edited the code with print. print("3") does not fire.

bool _checkConfiguration() => true;

  @override
  void initState() {
    _currentDate = widget._currentDate;
    _markedDateMap = widget._markedDateMap;

    if (_checkConfiguration()) {
      print("1"); // FIRES
      Future.delayed(Duration(seconds: 2), () {
        final calendarEntriesDataInitial =
            Provider.of<CalendarEntries>(context, listen: false);

        print("2"); // FIRES
        FutureBuilder<List<CalendarEntry>>(
            future: calendarEntriesDataInitial.getAll(),
            builder: (BuildContext context,
                AsyncSnapshot<List<CalendarEntry>> snapshot) {
              print("3"); // NOT FIRES. HERE´S A PROBLEM!
              if (snapshot.hasData &&
                  snapshot.connectionState != ConnectionState.waiting) {
                for (final entry in snapshot.data) {
                  setState(() {
                    _markedDateMap.add(
                        new DateTime(entry.dateTime),
                        new Event(
                          date: new DateTime(entry.dateTime),
                          title: 'Event 5',
                          icon: _eventIcon,
                        ));
                  });
                }
              }
            });
      });
    }

    super.initState();
  }

Jitesh Mohite · Accepted Answer · 2020-07-11 11:31:22Z

1

You have to use setState() for showing updated UI in map

setState(() {
    _markedDateMap.add(...)
    });

answered Jul 11, 2020 at 11:31

Jitesh Mohite

34.5k15 gold badges179 silver badges161 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Vueer Over a year ago

Not working. I also put an print("Test") into the FutureBuilder, but nothing in the console...

Jitesh Mohite Over a year ago

@asored: That means yout FutureBuilder itself not working. Right?

Vueer Over a year ago

Yes, seems to be like that.

Jitesh Mohite Over a year ago

use StreamBuilder instead of FutureBuilder

Vueer Over a year ago

I have to use FutureBuilder as type. My database requires that :( And in other places its working well, for example in the Widget Tree.... I´ll update my code with print examples. Just a moment..

Vueer · Accepted Answer · 2020-07-11 11:58:06Z

I found a solution: The FutureBuilder is a widget and can only by used in the widget three. Therefore I use another way to get my required values:

@override
  void initState() {
    _currentDate = widget._currentDate;
    _markedDateMap = widget._markedDateMap;

    Future.delayed(Duration.zero, () {
      final calendarEntriesDataInitial =
          Provider.of<CalendarEntries>(context, listen: false);

      calendarEntriesDataInitial.getAll().then((value) {
        if (value == null || value.isEmpty) {
          return;
        }

        for (final entry in value) {
          if (entry.dateTime != null) {
            final date = DateTime.parse(entry.dateTime);
            setState(() {
              _markedDateMap.add(
                  new DateTime(date.year, date.month, date.day),
                  new Event(
                    date: new DateTime(date.year, date.month, date.day),
                    title: entry.servicePartner,
                    icon: _eventIcon,
                  ));
            });
          }
        }
      });
    });

    super.initState();
  }

Collectives™ on Stack Overflow

Adding data to existing list from initState in Flutter (Async)

2 Answers 2

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related