main.dart

import 'package:client/providers/ShoppingListProvider.dart';
import 'package:client/screens/Home.dart';
import 'package:client/widgets/StatefulWrapper.dart';
import 'package:flutter/material.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:provider/provider.dart';

import 'auth/Auth.dart';

void main() => runApp(MultiProvider(
  providers: [
    ChangeNotifierProvider(create: (_) => Auth()),
    FutureProvider(create: (_) => ShoppingListProvider().loadShoppingLists(),
    ),
  ],
  child: MyApp(),
));

class MyApp extends StatelessWidget {
  final storage = new FlutterSecureStorage();

  @override
  Widget build(BuildContext context) {
    Future _tryToAuthenticate() async {
      String token = await storage.read(key: 'token');

      Provider.of<Auth>(context).attempt(token: token);
    }

    return StatefulWrapper(
      onInit: () => _tryToAuthenticate(),
      child: MaterialApp(
        title: 'Flutter Auth',
        theme: ThemeData(
          primaryColor: Colors.red[500],
          accentColor: Colors.yellow[600],
          fontFamily: 'Montserrat',
          textTheme: TextTheme(
            headline: TextStyle(fontSize: 36.0, fontWeight: FontWeight.bold, color: Colors.red),
            title: TextStyle(fontSize: 16.0, fontStyle: FontStyle.normal, fontWeight: FontWeight.w500),
            body1: TextStyle(fontSize: 14.0, fontFamily: 'Hind'),
          ),
          buttonTheme: ButtonThemeData(
            buttonColor: Colors.redAccent,
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(8.0)
            ),
            textTheme: ButtonTextTheme.primary, 
          ),
        ),
        home: Home(),
      ),
    );
  }
}

Provider Error

Error: Could not find the correct Provider<ShoppingListProvider> above this ShoppingList Widget

To fix, please:

  * Ensure the Provider<ShoppingListProvider> is an ancestor to this ShoppingList Widget
  * Provide types to Provider<ShoppingListProvider>
  * Provide types to Consumer<ShoppingListProvider>
  * Provide types to Provider.of<ShoppingListProvider>()
  * Always use package imports. Ex: `import 'package:my_app/my_code.dart';
  * Ensure the correct `context` is being used.

If none of these solutions work, please file a bug at:
https://github.com/rrousselGit/provider/issues

User-created ancestor of the error-causing widget was
    MaterialApp 
lib/main.dart:32
When the exception was thrown, this was the stack
#0      Provider.of 
package:provider/src/provider.dart:264
#1      ShoppingList.build 
package:client/…/shopping/ShoppingList.dart:8
#2      StatelessElement.build 
package:flutter/…/widgets/framework.dart:4009
#3      ComponentElement.performRebuild 
package:flutter/…/widgets/framework.dart:3941
#4      Element.rebuild 
package:flutter/…/widgets/framework.dart:3738
...

ShoppingListProvider.dart

import 'dart:convert';

import 'package:client/models/ShoppingListData.dart';
import 'package:dio/dio.dart' as Dio;
import 'package:flutter/material.dart';

import '../dio.dart';

class ShoppingListProvider extends ChangeNotifier {
  List<ShoppingListData> shoppingLists;

  get allLists => shoppingLists;

  get listCount => shoppingLists.length;

  Future<List<ShoppingListData>> loadShoppingLists() async {
    try {
      Dio.Response response = await dio().get('/shopping');
      Map<String, dynamic> jsonShoppingList = jsonDecode(response.data);

      shoppingLists =
          ShoppingList.fromJson(jsonShoppingList['data']).shoppingLists;

      return shoppingLists;
    } catch (e) {}

    return null;
  }
}

ShoppingLists.dart

import 'package:client/providers/ShoppingListProvider.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

class ShoppingList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var _shoppingLists = Provider.of<ShoppingListProvider>(context).allLists;
    print(_shoppingLists);

    return Scaffold(
      appBar: AppBar(title: Text('LetsShop - Your Shopping Lists')),
      body: Column(
        children: <Widget>[
          Expanded(
            child: _shoppingLists == null ? Text("No products lists found") : ListView.builder(
                itemCount: _shoppingLists.length,
                itemBuilder: (context, index) {
                  return Container(
                    child: Center(
                      child: Text('${_shoppingLists[index].name}'),
                    ),
                  );
                }),
          )
        ],
      ),
    );
  }
}