Flutter Integration with Hive(No-Sql)

flutter hive integration

Past couple of weeks I have studied flutter development. What I feel Flutter is more cooler than any other mobile development frameworks. So When I deep learn the widgets & API integration I thought to build offline first mobile application.

Setup

Download following dependencies to flutter project.

hive: ^1.4.4+1
path_provider: ^1.6.24
hive_flutter: ^0.3.1

And need to Add These Two As Dev Dependencies.

hive_generator: ^0.7.0+2
build_runner: ^1.8.0

Initialize the Hive database in Application Main Method.

void main() async {
  await Hive.initFlutter();
  runApp(MyApp());
}

What We are going to do is save User Object to Hive Database. First need to Create Object class.

import 'package:hive/hive.dart';
part 'user-model.g.dart';

@HiveType(typeId: 1)
class User {
  @HiveField(0)
  final String id;

  @HiveField(1)
  final String name;

  @HiveField(1)
  final int age;
  
  User({this.id, this.name, this.age});
}

Note : When Working with Hive database We have to write Adapter class for Each Object to do operations in hive database. But It is very tedious process & hard to write Adapters. For That one We have to use hive_generator . When we put part ‘user-model.g.dart’; & run following command It will Generate Adapter class for User Object. This will generate Adapter class name as “user-model.g.dart”

flutter pub run build_runner build

And We have to Register Generated Adapter in Main Method.

void main() async {
  await Hive.initFlutter();
  Hive.registerAdapter(UserAdapter());
  runApp(MyApp());
}

CRUD Operations

First need to Open Box for Adding Items

Future openBox() async {
  var directory = await getApplicationDocumentsDirectory();
  Hive.init(directory.path);
  box = await Hive.openBox('users');
  return;
}

1.Save Data

Future addData(List<User> allLocations) async {
  await box.clear();
  for (Location u in allLocations) {
    box.put(u.id, u);
  }
}

2. Retrieve Data

Future<List> _getAllUsers() async {
   await openBox();
   return box.toMap().values.toList();
 }

And That is all . It is simple & fast . Our Next article we will cover how to write offline first Application with hive & REST API.