cleema_communication.dart

//////////////////////////////////
// To run this gist, run: https://dartpad.dev/?id=c99cdde56d55cd1ac878cbaf2b5418c7
//////////////////////////////////
import 'package:riverpod/riverpod.dart';

/// A Provider that reads a json file and decodes it into a [Configuration].
final authProvider = FutureProvider<String>((_) async {
  print("executed authProvider");
  return "my-auth-state";
});

final challengeListRepository =
    AsyncNotifierProvider<ChallengeListRepositoryNotifier, List<String>>(
      ChallengeListRepositoryNotifier.new,
    );

class ChallengeListRepositoryNotifier extends AsyncNotifier<List<String>> {
  void add(String listEl) async {
    print("AJAX Call to create list element (awaited)");
    await Future.delayed(Duration(seconds: 2));
    print("Invalidating...");
    
    // Reload my data -> this sets "isLoading=true" on the async value
    // -> good for loading indicator.
    // -> when build() has completed again (=new data was fetched), isLoading=false again.
    ref.invalidateSelf(); 
  }

  @override
  Future<List<String>> build() async {
    print("-> DOING AJAX CALL (faked)");
    await Future.delayed(Duration(seconds: 2));
    print("<- received response");
    return ["CHallenge 1", "Challenge 2 " + DateTime.now().toIso8601String()];
  }
}

Future<void> main() async {
  // Where the state of our providers will be stored.
  // Avoid making this a global variable, for testability purposes.
  // If you are using Flutter, you do not need this.
  final ref = ProviderContainer();

  // Initial fetch
  ref.listen(challengeListRepository, (prev, next) {
    print ("Loading: " + next.isLoading.toString());
    // TODO: WHY DOES THIS NOT PRINT? (the "doing ajax call" above prints")
    if (next.value == null) {
      print("Challenge is still null: ");
    }

    print("Received challenge list: " + next.value!.join(", "));
  });

  // do a change
  ref.read(challengeListRepository.notifier).add("My new element");
}