Flutter Local Storage: Simplify Data Persistence with Hive

Unlock the Power of Local Data Persistence in Flutter with Hive

When it comes to building a mobile app, storing data locally and persisting it between app launches is crucial. From storing customer information to tracking game scores, every app requires a reliable way to handle data. Flutter provides several options for local data persistence, but Hive stands out as a fast, secure, and cross-platform solution.

Why Choose Hive?

Hive is a lightweight, key-value database solution written in pure Dart, making it an ideal choice for Flutter developers. Its cross-platform compatibility means it runs seamlessly on mobile, desktop, and web platforms, with no native dependencies. Plus, Hive’s speed and security features make it an attractive option for storing sensitive data.

Getting Started with Hive

To get started with Hive, create a new Flutter project and add the Hive and hive_flutter packages to your pubspec.yaml file. Then, replace the content of your main.dart file with the following code:

“`dart
import ‘package:flutter/material.dart’;
import ‘package:hive/hive.dart’;
import ‘package:hiveflutter/hiveflutter.dart’;

void main() async {
await Hive.initFlutter();
await Hive.openBox(‘peopleBox’);
runApp(MyApp());
}

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: ‘Hive Demo’,
home: InfoScreen(),
);
}
}
“`

Understanding Boxes in Hive

In Hive, data is stored in boxes, which are similar to tables in an SQL database. Boxes are flexible and can handle simple relationships between data. Before accessing data, you must open the box, which loads the entire content into memory.

Storing Sensitive Information with Encrypted Boxes

Hive provides support for AES-256 encryption, along with a helper function for generating an encryption key using the Fortuna algorithm. To store sensitive information securely, use an encrypted box and store the encryption key using the fluttersecurestorage package.

Performing CRUD Operations

To perform create, read, update, and delete (CRUD) operations, define the basic operations in the InfoScreen StatefulWidget. The structure of this class will be as follows:

“`dart
class InfoScreen extends StatefulWidget {
@override
_InfoScreenState createState() => _InfoScreenState();
}

class _InfoScreenState extends State {
Box _box;

@override
void initState() {
super.initState();
_box = Hive.box(‘peopleBox’);
}

@override
void dispose() {
_box.close();
super.dispose();
}

// CRUD operations
}
“`

Using Custom Objects with TypeAdapter

Hive supports storing custom model classes using TypeAdapters, which generate the to and from binary methods. To use a custom class, annotate the model class and generate the TypeAdapter using the hive_generator package.

Building the Final App

The final app will comprise three screens: AddScreen for storing user information, InfoScreen for displaying user information and deleting data, and UpdateScreen for updating user information. The code for each screen is provided in the example repository.

Conclusion

Hive is a powerful and flexible solution for local data persistence in Flutter. With its speed, security, and cross-platform compatibility, Hive is an ideal choice for any Flutter developer. By following this guide, you can build a robust and efficient app that meets your data storage needs.