fromJson factory constructor

[SunlightBro]

I really like the factory constructor syntax from json_serializable, to be able to call Model.fromJson(uint8List).
I'm aware this would just be syntactic-sugar with out much value, but could help migrating from json_serializable to crimson, and it could be just optionally.

Example what I mean

If there is a factory constructor that returns _$<className>(buffer) (or some other name convention)

@json
class Model {
  // ...
  factory Model.fromJson(List<int> buffer) => _$Model(buffer);
}

then generate additional extensions like so:

Model _$Model(List<int> buffer) => ModelExt.fromJson(buffer);

extension ModelExt on Model {
  static Model fromJson(List<int> buffer) {
    final crimson = Crimson(buffer);
    return crimson.readModel();
  }

  Uint8List toJson() {
    final writer = CrimsonWriter();
    writer.writeModel(this);
    return writer.toBytes();
  }
}

extension ModelList on List<Model> {
  static List<Model> fromJson(List<int> buffer) {
    final crimson = Crimson(buffer);
    return crimson.readModelList();
  }

  Uint8List toJson() {
    final writer = CrimsonWriter();
    writer.writeModelList(this);
    return writer.toBytes();
  }
}

then you can call

final Model model = Model.fromJson(singleModelUint8List);
final Uint8List foo = model.toJson();

final List<Model> list = ModelList.fromJson(listUint8List);
final Uint8List bar = list.toJson();

If this is something you want I can create a PR.

[simc]

I really like this idea. I think it would be a great addition 🙏

[SunlightBro]

@simc After working on it for a while now, the only way to make it work (together with freezed) is to always use @Freezed(fromJson: false, toJson: false)

Example

@Freezed(fromJson: false, toJson: false)
class FJFreezed with _$FJFreezed {
// ignore: invalid_annotation_target
@json
const factory FJFreezed({
  required String name,
  required int age,
}) = _FJFreezed;

factory FJFreezed.fromJson(List<int> buffer) => _$FJFreezedFromJson(buffer);
}

which makes it quite unintuitive to use.