How to update a "ChangeNotifierProxyProvider" in the new version of the flutter?

Question

I am trying to update an old Flutter code, this is the original code:

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider.value(
          value: Auth(),
        ),
        ChangeNotifierProxyProvider<Auth, Products>(
          builder: (ctx, auth, previousProducts) => Products(
                auth.token,
                auth.userId,
                previousProducts == null ? [] : previousProducts.items,
              ),
        ),

And I tried to modify it like below:

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider.value(
          value: Auth(),
        ),
        ChangeNotifierProxyProvider<Auth, Products>(
          create: (ctx) => Products(), 
          update: (ctx, auth, previousProducts) => Products(
            auth.token as String,
            auth.userId as String,
            previousProducts == null ? [] : previousProducts.items,
          ),
        ),

But still I have an error in the following line that I don't know how to resolve:

      create: (ctx) => Products(), 

3 positional argument(s) expected, but 0 found. Try adding the missing arguments.dartnot_enough_positional_arguments (new) Products Products( String authToken, String userId, List _items, )

And when I try to add arguments like what I passed in the update part, it gives me different kind of other errors.

How should I renew this old code?

Answer 1

try this create: (_) => Products('', []),