Hive In Flutter

Made for Zemin Istanbul Presantation

Basically, the application saves the basic data types and custom generated data classes to the local storage.

Getting Started

Dependencies 🧰

Package

dependencies:
  hive_flutter: ^1.1.0 //add this line

dev_dependencies:
  build_runner: ^2.2.1 //add this line
  hive_generator: ^1.1.3 //add this line

• hive_flutter

Provides operations on the local storage.

• build_runner

Provides a concrete way of generating files using Dart code.

• hive_generator

Provides automatic generation of TypeAdapters for almost any class.

Project Architecture Output

.
├── lib                  
    ├── core
        └── service
            ├── cache
                ├── base_cache_manager.dart
                └── cache_enums.dart   
    ├── model
        ├── todo_model.dart
        └── todo_model.g.dart
    └── product
        └── todo
            ├── todo_service.dart
            └── todo_view.dart
└── main.dart

Base Functions & Hive Classes

Base Functions

• Initialize Hive

  await Hive.initFlutter();

• Open Hive Box

Future<void> boxInit() async {
  await Hive.openBox(boxName);
}

• Add item to box with auto increment key

Future<void> addItemWithAutoIncrementKey(T item) async {
  await _box!.add(item);
}

• Add item to box with custom key

Future<void> addItemWithCustomKey(dynamic key, T item) async {
  await _box!.put(key, item);
}

• Get item from box

T? getItem(dynamic key) {
  return _box!.get(key);
}

• Remove item from box

Future<void> removeItem(dynamic key) async {
  await _box!.delete(key);
}

• Clear box

Future<void> clearBox() async {
  await _box!.clear();
}

• Close box

Future<void> closeBox() async {
  await _box!.close();
}

Hive Classes

• Class Architecture

import 'package:hive_flutter/adapters.dart';
part 'todo_model.g.dart';

@HiveType(typeId: 1)
class Todo {
  @HiveField(0)
  int? userId;
  @HiveField(1)
  int? id;
  @HiveField(2)
  String? title;
  @HiveField(3)
  bool? completed;

  Todo({this.userId, this.id, this.title, this.completed});

  Todo.fromJson(Map<String, dynamic> json) {...}
  Map<String, dynamic> toJson() {...}
}

• Generate Part File Command

flutter pub run build_runner build

Create an Manager from Generic Cache Manager

• initialize

final BaseCacheManager<Todo> _todoCacheManager = BaseCacheManager<Todo>(boxName: CacheBoxNames.todo);
Future<void> serviceInit() async {
  await _todoCacheManager.boxInit();
}

Usage 🛠

When the manager is generated and initialized, it can accesses and uses generic cache manager functions.

await _todoCacheManager.boxInit();
_todoCacheManager.getItemList();
await _todoCacheManager.addItemList(items);
await _todoCacheManager.clearBox();
...

Source

Hive Documentation