Flutter: Local storage demo app using Drift

This is a Flutter project that demonstorates how to store user data on a local device. This project was extended from the previous one.

In my previous project, any change the user added/deleted on the date list was only alive within a run, and it was all gone when the app finished. However, in real-world apps, those data should be retained and be accessible in the next run.

In this project, I implemented local storage to persist the user's latest edit to a device. Now, when I stop the app and then restart, the changes I made in the previous session is still valid, as the following GIF shows.

Local Storage options in Flutter

Flutter has some options for local storage.

• shared_preference: Lightweight key-value storage. It's a Flutter plugin (official doc)
• Using File class and path_provider package: Writing data into files in local storage (official doc)
• sqflite: SQLite implementation for Flutter (doc)
• Hive: Lightweight and buzzing-fast key-value database for Flutter and Dart (doc)
• Isar: Super fast cross-platform database for Flutter (doc)
• Drift: Type-safe reactive persistence library for Flutter built on top of SQLite (doc)
• ObjectBox: NoSQL, object-oriented database with excellent performance (doc)

shared_preference will be sufficient for small data and could be the first choice. But considering versatility and scalability in the future, I decided to explore a database package here.

Then, I thought of Hive because it seemed fast and lightweight as well as simple to use. However, I encountered some discussion on the internet and I noticed Hive hadn't been maintained for some time. After seeking alternatives, I decided to try Drift here. Drift could be a bit complicated for beginners like me to understand (actually I felt so), but Type safety and availability of Stream queries (I don't use this feature in this project, though) are valuable features if they are at hand.

Code

lib
 ┣ data  // represents data layer
 ┃ ┣ models
 ┃ ┃ ┣ data_todate.dart  // Drift database model
 ┃ ┃ ┗ data_todate.g.dart  // Autogenerated by Drift
 ┃ ┗ repository
 ┃ ┃ ┗ data_todate_repo.dart  // implementation of data repository
 ┣ domain  // represents domain layer
 ┃ ┣ models
 ┃ ┃ ┗ todate.dart
 ┃ ┗ repository
 ┃ ┃ ┗ todate_repo.dart
 ┣ feature  // represents feature/UI layer
 ┃ ┣ pages
 ┃ ┃ ┣ add
 ┃ ┃ ┃ ┗ add.dart
 ┃ ┃ ┣ detail
 ┃ ┃ ┃ ┣ date_area.dart
 ┃ ┃ ┃ ┣ detail.dart
 ┃ ┃ ┃ ┣ history_detail.dart
 ┃ ┃ ┃ ┗ memo_area.dart
 ┃ ┃ ┣ history
 ┃ ┃ ┃ ┗ history.dart
 ┃ ┃ ┗ toplist
 ┃ ┃ ┃ ┗ toplist.dart
 ┃ ┗ shared
 ┃ ┃ ┣ app.dart
 ┃ ┃ ┣ bottom_navbar.dart
 ┃ ┃ ┣ router.dart
 ┃ ┃ ┣ todate_cubit.dart
 ┃ ┃ ┣ todate_provider.dart
 ┃ ┃ ┗ todate_rootview.dart
 ┗ main.dart

Platform

In develpment, I selected Windows app as my target device.

Flutter resources

A few resources to get you started if this is your first Flutter project:

• Lab: Write your first Flutter app
• Cookbook: Useful Flutter samples

For help getting started with Flutter development, view the online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.