Flutter: Generating Hive Adapter but hive uses different name?

Question

I recently introduced a custom class for my weather app to store all of data, now I want to save it via Hive. I run the generator and everything is fine, but when I run the app and try to call box.put(), it gives me an error saying unknown type. my class:

@HiveType(typeId: 0)
class WeatherData {
  @HiveField(0)
  IconData? mainIcon;
  @HiveField(1)
  String? countryname;
  @HiveField(2)
  String? temperature;
  @HiveField(3)
  String? tempfeelslike;
  @HiveField(4)
  String? humidity;
  @HiveField(5)
  String? windSpeed;
  @HiveField(6)
  String? mainWeather;
  @HiveField(7)
  String? weatherDescription;
  @HiveField(8)
  String? pressure;
  @HiveField(9)
  String? sunrise;
  @HiveField(10)
  String? sunset;
  @HiveField(11)
  String? lastUpdated;
  @HiveField(12)
  String? lastUpdatedFull;
}

My main function:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final appDocumentsDir = await getApplicationDocumentsDirectory();
  String path = appDocumentsDir.path;
  Hive..init(path)..registerAdapter<WeatherData>(WeatherDataAdapter());
  runApp(MainApp());
}

error I'm getting: "Cannot write, unknown type: WIData. Did you forget to register an adapter?" the thing is, WIData is never declared or even mentioned, I also checked auto generated adapter but never saw WIData in any part of my project

I couldn't find anything related to my issue, but these are things I tried:

• Flutter clean
• re-generating adapter
• re-building the app

Answer 1

Ok, first delete the mybox.hive file or the name you used from the my documents folder to rule out problems.

then try to convert the icondata to map and save them as map not as icondata, and use a function to convert from icondata to map and vice versa. here I leave an example

import 'package:flutter/material.dart';
import 'package:hive/hive.dart';
import 'package:path_provider/path_provider.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final appDocumentsDir = await getApplicationDocumentsDirectory();
  String path = appDocumentsDir.path;
  Hive
    ..init(path)
    ..registerAdapter<WeatherData>(WeatherDataAdapter());

  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late Box box;
  IconData? iconDataToday;
  WeatherData? weatherDataToday;

  @override
  void initState() {
    super.initState();

    WidgetsBinding.instance.addPostFrameCallback((_) async {
      box = await Hive.openBox('myBox');
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Material App',
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Material App Bar'),
        ),
        body: Center(
          child: Column(
            children: [
              iconDataToday == null ? const SizedBox() : Icon(iconDataToday),
              weatherDataToday == null
                  ? const SizedBox()
                  : Text(
                      "Today: ${weatherDataToday!.countryname} \n Temperature: ${weatherDataToday!.temperature}"),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: FilledButton(
                    onPressed: () async {
                      WeatherData weatherData = WeatherData()
                        ..mainIcon = iconDataToMap(Icons.ac_unit)
                        ..countryname = "Cuba"
                        ..temperature = "30"
                        ..tempfeelslike = "30"
                        ..humidity = "30"
                        ..windSpeed = "30"
                        ..mainWeather = "30"
                        ..weatherDescription = "30"
                        ..pressure = "30"
                        ..sunrise = "30"
                        ..sunset = "30"
                        ..lastUpdated = "30"
                        ..lastUpdatedFull = "30";
                      box.put('today', weatherData);
                    },
                    child: const Text("insert today")),
              ),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: FilledButton(
                    onPressed: () async {
                      WeatherData weatherData = box.get('today');
                      setState(() {
                        iconDataToday = iconDataFromMap(
                            weatherData.mainIcon as Map<dynamic, dynamic>);
                        weatherDataToday = weatherData;
                      });
                    },
                    child: const Text("Get today")),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

//!
/// Icon data to map and map to icon data
Map iconDataToMap(IconData icon) {
  return {
    'codePoint': icon.codePoint,
    'fontFamily': icon.fontFamily,
    'fontPackage': icon.fontPackage
  };
}

IconData iconDataFromMap(Map map) {
  return IconData(map['codePoint'],
      fontFamily: map['fontFamily'], fontPackage: map['fontPackage']);
}
///////////////////////////////

@HiveType(typeId: 0)
class WeatherData {
  @HiveField(0)
  Map? mainIcon; //! Map no Icondata
  @HiveField(1)
  String? countryname;
  @HiveField(2)
  String? temperature;
  @HiveField(3)
  String? tempfeelslike;
  @HiveField(4)
  String? humidity;
  @HiveField(5)
  String? windSpeed;
  @HiveField(6)
  String? mainWeather;
  @HiveField(7)
  String? weatherDescription;
  @HiveField(8)
  String? pressure;
  @HiveField(9)
  String? sunrise;
  @HiveField(10)
  String? sunset;
  @HiveField(11)
  String? lastUpdated;
  @HiveField(12)
  String? lastUpdatedFull;
}

class WeatherDataAdapter extends TypeAdapter<WeatherData> {
  @override
  final typeId = 0;

  @override
  WeatherData read(BinaryReader reader) {
    return WeatherData()
      ..mainIcon = reader.read()
      ..countryname = reader.read()
      ..temperature = reader.read()
      ..tempfeelslike = reader.read()
      ..humidity = reader.read()
      ..windSpeed = reader.read()
      ..mainWeather = reader.read()
      ..weatherDescription = reader.read()
      ..pressure = reader.read()
      ..sunrise = reader.read()
      ..sunset = reader.read()
      ..lastUpdated = reader.read()
      ..lastUpdatedFull = reader.read();
  }

  @override
  void write(BinaryWriter writer, WeatherData obj) {
    writer
      ..write(obj.mainIcon)
      ..write(obj.countryname)
      ..write(obj.temperature)
      ..write(obj.tempfeelslike)
      ..write(obj.humidity)
      ..write(obj.windSpeed)
      ..write(obj.mainWeather)
      ..write(obj.weatherDescription)
      ..write(obj.pressure)
      ..write(obj.sunrise)
      ..write(obj.sunset)
      ..write(obj.lastUpdated)
      ..write(obj.lastUpdatedFull);
  }
}