hive_object.md

HiveObject

When you store custom objects in Hive you can extend HiveObject to manage your objects easily.HiveObject provides the key of your object and useful helper methods like save() or delete().

Here is an example how to use HiveObject:

import 'package:hive/hive.dart';

void main() async {
  Hive.registerAdapter(PersonAdapter());
  var persons = await Hive.openBox('persons');

  var person = Person()
    ..name = 'Lisa';

  persons.add(person); // Store this object for the first time

  print('Number of persons: ${persons.length}');
  print("Lisa's first key: ${person.key}");

  person.name = 'Lucas';
  person.save(); // Update object

  person.delete(); // Remove object from Hive
  print('Number of persons: ${persons.length}');

  persons.put('someKey', person);
  print("Lisa's second key: ${person.key}");
}

@HiveType()
class Person extends HiveObject {
  @HiveField(0)
  String name;
}

class PersonAdapter extends TypeAdapter<Person> {
  @override
  final typeId = 0;

  @override
  Person read(BinaryReader reader) {
    return Person()..name = reader.read();
  }

  @override
  void write(BinaryWriter writer, Person obj) {
    writer.write(obj.name);
  }
}

?> You also need to extend HiveObject if you want to use queries.