dvToEncodable function

Object? dvToEncodable(Object? value)

value as something jsonEncode can write: a model through its registered serializer, found by its runtime type, and maps, lists and the models inside them the same way, all the way down; a DateTime as ISO 8601.

A generated model's toJson is an extension member, which jsonEncode cannot see -- so a backend function returning a model, or a model holding another, failed with "Converting object to an encodable object failed". Anything else is returned as it is, for jsonEncode to write or refuse.

Implementation

Object? dvToEncodable(Object? value) {
  if (value == null || value is num || value is bool || value is String) {
    return value;
  }
  if (value is DateTime) return value.toIso8601String();
  if (value is Map) {
    return <String, Object?>{
      for (final MapEntry<Object?, Object?> entry in value.entries)
        '${entry.key}': dvToEncodable(entry.value),
    };
  }
  if (value is Iterable) {
    return <Object?>[for (final Object? item in value) dvToEncodable(item)];
  }
  final Map<String, Object?> Function(Object?)? serializer = dvModelSerializers[value.runtimeType];
  if (serializer != null) return dvToEncodable(serializer(value));
  return value;
}