Description
I'm looking at how it can be possible to support Iterators that are not supported by default in
json_serializable.
Examples are ObservableList from Mobx or BuiltList from built_collection.
I am able to implement a basic solution, however it requires a JsonConverter for every type you plan to use with those Lists.
One example here: https://mobx.pub/guides/json shows that it works, but that Converter only works for ObservableList<Todo>, not ObservableList<T>. (And of course T in this case is either a basic JSON type or has a toJson method).
Another example from my codebase using BuiltList.
class BuiltListConverterNote
implements JsonConverter<BuiltList<Note>, List<Map<String, dynamic>>> {
const BuiltListConverterNote();
@override
BuiltList<Note> fromJson(List<Map<String, dynamic>> json) =>
BuiltList.of(json.map((x) => Note.fromJson(x)));
@override
List<Map<String, dynamic>> toJson(BuiltList<Note> list) =>
list.map((x) => x.toJson()).toList();
}
@JsonSerializable()
class ServiceOrder {
@BuiltListConverterNote()
final BuiltList<Note> notes;
}The above works, but again I need to create that JsonConverter for every type like Note I want to use.
I'm looking for something like the following.
final factories = <Type, Function>{
Note: (Map<String, dynamic> json) => Note.fromJson(json)
};
T make<T>(Type type, Map<String, dynamic> x) {
return factories[type](x);
}
class BuiltListConverter<T>
implements JsonConverter<BuiltList<T>, List<Map<String, dynamic>>> {
const BuiltListConverter();
@override
BuiltList<T> fromJson(List<Map<String, dynamic>> json) =>
BuiltList.of(json.map((x) => make(T, x)));
@override
List<Map<String, dynamic>> toJson(BuiltList<T> list) =>
list.map((x) => (x as dynamic).toJson()).toList();
}
@JsonSerializable()
class ServiceOrder {
@BuiltListConverter()
final BuiltList<Note> notes;
}This currently doesn't work.
Error running JsonSerializableGenerator
Could not generate `fromJson` code for `notes`.
None of the provided `TypeHelper` instances support the defined type.
package:hx_tech_app/domain/models.dart:28:25
╷
28 │ final BuiltList<Note> notes;
│ ^^^^^
╵
Is there a different way I should approach this? Perhaps a TypeHelper?
I have been looking online for documentation for adding TypeHelper but I can't find any anywhere and the example in this repo does not add TypeHelpers.