After upgrade from 1.3.1 to 1.4.0 get_storage i get type 'LastCall' is not a subtype of type 'Map<String, dynamic>' error about get_storage

[hhstore]

ref:

• dart-lang/sdk#46854

solution:

• fix for dart null safety.
• like this example:

  /// get many:
  Map<String, UserEntity> users() {
    var key = keys.users();

    /// (UserEntity, has fromJson, toJson)
    var raw = kv.read(key) ?? {};
    print('users:$raw, ${raw.runtimeType}');

    // if (raw is Map<String, UserEntity>) {
    //   return raw;
    // }

    // return raw;
    var result = <String, UserEntity>{};

    raw.forEach((key, value) {
      print('$key, $value, ${value.runtimeType}');
      result[key] = value is UserEntity ? value : UserEntity.fromJson(value); // TODO: here!!!
      // result[key] = (value as UserEntity?)!;
    });

    return result;
    // return raw ?? {};
    // return Map<String, UserEntity>.from(out ?? {});
  }

key points:

• required: forEach + value is UserEntity

  raw.forEach((key, value) {}


  result[key] = value is UserEntity ? value : UserEntity.fromJson(value); // TODO: here!!!

[jpandco]

yes the same error. if you write Model then read he will return from memory and the return will keep the Type Model.
but if the model was not in memory he will get the model from storage and the return will be _InternalLinkedHashMap<String, dynamic>

[dreamer2q]

When your data is stored in memory, you can get the exact type as you want, otherwise you will get json decoded data from LocalStorage (usually typed Map or List depending your data type).

Therefore, you have to check the data type before you try parse fromJson.

This is the problem of flutter, you have to compromise.

[iammazharul]

may be i am late, but i think it's still helpful. because me also faced the same problem. in my case i am forget to convert it in JSON format before wright action.In my case:

error: get_storage is not a subtype of type 'Map<String, dynamic>'
wrong way:
box.write('user', data.userData);

right way:

          UserData userData;
          GetStorage box = GetStorage();
          box.write('user', data.userData.toJson());

userData = UserData.fromJson(box.read('user'));

[aminkhan1]

i had this problem. i fix this problem like this
if (store.read('docs') is DocsModel) { return model = store.read('docs'); } else { return model = DocsModel.fromJson(store.read('docs')); }

[halkportal970]

After I downgrade to 1.3.2 code works fine.

[ashbressler]

I'm experiencing the same.

Some of my observations are that the first time after loading the app GetStorage().read returns a json array. However once I call GetStorage().write then .read returns the Model that I wrote, not the JSON representation of that Model.

[jpandco]

After 1.4.0 upgrade, I get
type 'LastCall' is not a subtype of type 'Map<String, dynamic>'
error.
I have a model called LastCall, and I store data as json .
First call of loadLastCallList() function works perfect. Bu second time, third time etc fails.
First time list variable is a [0]: Map
But the other times list variable is a [0]:LastCall
for that fromJson fails to convert list[i]

Why list variable is first time is a Map but the other times is a Model(LastCall)
List list = GetStorage().read("lastCallList");
I am excepting it all the time as a Map variable.

Future<void> loadLastCallList() async {
    var tempList = List<LastCall>();
      List<dynamic> list = GetStorage().read("lastCallList");
      if (list != null) {
        for (var i = 0; i < list.length; i++) {
          LastCall lastCall = LastCall.fromJson(list[i]);
          tempList.add(lastCall);
        }
      } else {
        lastCallList.clear();
      }
      lastCallList.assignAll(tempList);
}

i think this will fix your error

  Future<void> loadLastCallList() async {
    var tempList = List<LastCall>();
    var _data = GetStorage().read("lastCallList");
    
    var list = _data is List<LastCall> ? _data : Map<String, dynamic>.from(_data).entries.toList();
    
    if (list != null) {
      for (var i = 0; i < list.length; i++) {
        var _lastCall = list[i] is LastCall ? list[i] : LastCall.fromJson(list[i]);
        tempList.add(_lastCall);
      }
    } else {
      lastCallList.clear();
    }
    lastCallList.assignAll(tempList);
  }

[AlirezaDaryani]

same problem, i build model data with fromJson and toJson, but 'read' dose not give me my model.

[hhstore]

may be i am late, but i think it's still helpful. because me also faced the same problem. in my case i am forget to convert it in JSON format before wright action.In my case:

error: get_storage is not a subtype of type 'Map<String, dynamic>'
wrong way:
box.write('user', data.userData);

right way:

          UserData userData;
          GetStorage box = GetStorage();
          box.write('user', data.userData.toJson());

userData = UserData.fromJson(box.read('user'));

Hive DB:

• isar/hive#126
• like HiveDB: https://github.com/hivedb/hive#store-objects
• use hive_generator automatically generate TypeAdapters for almost any class.
• register a TypeAdapter which converts the object from and to binary form.
• https://docs.hivedb.dev/#/custom-objects/generate_adapter

Protobuf:

• The data definition for hive, very similar to the way protobuf is defined.
• https://github.com/dart-lang/protobuf

MsgPack:

• https://pub.dev/packages/msgpack_dart
  • https://github.com/knopp/msgpack_dart
• https://github.com/butlermatt/msgpack2
• https://github.com/ivoleitao/stash/tree/develop/packages/stash_hive
• https://pub.dev/packages/stash_hive
• https://msgpack.org/

FlatBuffers:

• Google FlatBuffers.
• https://github.com/google/flatbuffers
• dart lib: https://github.com/google/flatbuffers/blob/master/dart/README.md
  • https://pub.dev/packages/flat_buffers

My suggestion:

• In fact, get storage can directly support protobuf or msgpack to define the data model. Wouldn't it be better?
• The hive's way, a bit Inconvenient.
• @jonataslaw