How to implement a lazy loading behavior outside the Flutter scope?

[YuriHeiko]

I didn't find how to create a kind of question. Tell me please if it's inappropriate I will remove it.

I want to read my CDN assets lazily. Does my approach have any flaws?

// asset.dart
@freezed
class Asset with _$Asset {
  static final ProviderContainer _providerContainer = ProviderContainer();

  const factory Asset({
    @JsonKey(ignore: true) String? id,
    required String parentId,
    required String path,
    required Devices device,
    required DateTime timestamp,
  }) = _Asset;

  factory Asset.fromJson(Map<String, dynamic> json) => _$AssetFromJson(json);

  const Asset._();

  Future<Uint8List> get assetAsBytes =>
      _providerContainer.read(cdnRepositoryProvider).load(path);
}


// cdn_repository_provider.dart
final cdnRepositoryProvider = Provider.autoDispose<CdnRepository>(
    (ref) => CdnRepository(storage: ref.read(firebaseStorageProvider)));

class CdnRepository {
  final FirebaseStorage _storage;

  CdnRepository({required FirebaseStorage storage}) : _storage = storage;

  Future<Uint8List> load(String path) async {
    final data = await _storage.ref(path).getData();
    return data!.buffer.asUint8List();
  }
}

P.S. Could you please also briefly explain what is wrong with calling ref.read() inside the body of a Provider?

[rrousselGit]

You shouldn't create a ProviderContainer.
That assertAsBytes is also anti-pattern.

Instead, consider making a provider:

final bytesForAssetPathProvider = FutureProvider.autoDispose.family<Uint8List, String>((ref, path) async {
  final repository = ref.watch(cdnRepositoryProvider);

  return repository.load(path);
});

[YuriHeiko]

@rrousselGit got it, thank you for the quick response!

[YuriHeiko]

Unfortunately, I couldn't mark your reply as an answer due to GitHub issues - it responses with the 422 code when I try.