Hive Box not updating after clearing in other dart file/class - flutter

Question

i am clearing a hive box and updating it in the very next line.
The update can be seen in the same file code (through debugging).
But somehow for the other stateless widget/class/file box is empty.
boxT.clear() ;
setState(() {
boxT.addAll({
[count2, totalEntries]
});});
Reason for clearing the box on everytime a specific button is pressed: I am adding a map. addAll() simply creates another entry. i dont want it. i have also tried put and putall but they are only showing the value and not the key.

Answer 1

That's because Hive is NOT a state management tool, if you add/remove something to/from your box, you need to let your state know. You should have a global state that listens to changes from that Box.
Example with a ValueNotifier.
class ItemsNotifier extends ValueNotifier<List<Item>> {
ItemsNotifier() : super(getItemsFromBox());
List<Item> _items = getItemsFromBox();
#override
List<Item> get value => _items;
void addItem(Item item) {
addItemToBox(item);
_items = getItemsFromBox();
notifyListeners();
}
Future<void> deleteAll() async {
await clearBox();
_items = getItemsFromBox();
notifyListeners();
}
}
List<Item> getItemsFromBox() {
return Hive.box<Item>('items').values.toList();
}
Future<void> addItemToBox(Item item) async {
await Hive.box<Item>('items').add(item);
}
Future<void> clearBox() async {
await Hive.box<Item>('items').clear();
}
class MainPage extends StatefulWidget {
const MainPage({Key? key}) : super(key: key);
#override
State<MainPage> createState() => _MainPageState();
}
class _MainPageState extends State<MainPage> {
late final ItemsNotifier _notifier;
#override
void initState() {
_notifier = ItemsNotifier();
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: ExampleWidget(notifier: _notifier),
floatingActionButton: FloatingActionButton(
onPressed: _notifier.deleteAll,
child: const Icon(Icons.delete),
),
);
}
#override
void dispose() {
_notifier.dispose();
super.dispose();
}
}
class ExampleWidget extends StatelessWidget {
const ExampleWidget({required this.notifier, Key? key}) : super(key: key);
final ItemsNotifier notifier;
#override
Widget build(BuildContext context) {
return ValueListenableBuilder<List<Item>>(
valueListenable: notifier,
builder: (context, items, _) {
return ListView.builder(
itemBuilder: (context, index) => ListTile(
title: Text(items[index].title),
),
itemCount: items.length,
);
},
);
}
}
Note that if you have multiple pages using the data from this box, I would recommend using something like Provider and having a ChangeNotifier instead of the ValueNotifier or using flutter_bloc and having a Repository that handles communication with Hive.