valuenotifier_provider

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';


void main() {
  runApp(
    Provider(
      create: (context) => AppValueNotifier(),
      child: MyApp()
    )
  );
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Column(
          children: [
            TriggerWidget(),
            Expanded(
              child: MyWidget(),
            )
          ]
        ),
      ),
    );
  }
}

class Food {
  final String name;
  Food({ required this.name });
}

class AppValueNotifier
{
  ValueNotifier<List<Food>> valueNotifier = ValueNotifier([]);

  void updateDealsList(List<Food> list)
  {
    valueNotifier.value = list;
    print('DEAL LIST IN CLASS: ${ valueNotifier.value}');
  }
  
  List<Food> getDealList()
  {
    return valueNotifier.value;
  }
}

class TriggerWidget extends StatelessWidget {
  
  @override
  Widget build(BuildContext context) {
    
    AppValueNotifier appValueNotifier = Provider.of<AppValueNotifier>(context, listen: false);
    
    return TextButton(
      child: const Text('Trigger Adding Items!'),
      onPressed: () {
        appValueNotifier.updateDealsList([
            Food(name: 'Food 1'),
            Food(name: 'Food 2'),
          ]);
      },
    );
  }
        
}

class MyWidget extends StatelessWidget {
 
  
  @override
  Widget build(BuildContext context) {
    
    AppValueNotifier appValueNotifier = Provider.of<AppValueNotifier>(context, listen: false);
    
    return ValueListenableBuilder(
        valueListenable: appValueNotifier.valueNotifier,
        builder: (context, List<Food> value, widget) {

          var list = value;

          return ListView.builder(
            itemCount: list.length,
            itemBuilder: (context, index) {
              return Text(list[index].name);
            }
        );
      },
    );
  }
}