flutter_offline_queue #

A Flutter/Dart package to queue API requests when offline and automatically retry them when the device goes back online.

Features #

• Automatically detects internet connectivity changes
• Queues HTTP requests (GET, POST, PUT, DELETE) when offline
• Persists queued requests locally using SQLite (sqflite)
• Retries all pending requests once connectivity is restored
• Allows handling success and failure callbacks for retried requests

Getting Started #

Installation #

Add this to your pubspec.yaml:

dependencies:
  flutter_offline_queue: ^1.0.0

Then run:

flutter pub get

Usage #

Import the package:

import 'package:flutter_offline_queue/flutter_offline_queue.dart';

Initialize the queue early in your app (e.g., in main()):

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await OfflineQueue.instance.init();
  runApp(MyApp());
}

Add requests like this:

// POST request example
await OfflineQueue.instance.post(
  url: 'https://your-api.com/endpoint',
  headers: {'Authorization': 'Bearer your_token'},
  body: {'key': 'value'},
);

// GET request example
await OfflineQueue.instance.get(url: 'https://your-api.com/items');

Callbacks #

You can set callbacks in initState to listen for retried requests:

OfflineQueue.instance.onRequestRetried = (request) {
  print('Request retried: ${request.method} ${request.url}');
};

OfflineQueue.instance.onRequestFailed = (request, error) {
  print('Request failed: ${request.method} ${request.url}, error: $error');
};

Supported Methods #

• GET
• POST
• PUT
• DELETE

Limitations & Notes #

• Only basic JSON request bodies are supported.
• Headers should be provided as a Map<String, String>.
• Make sure your API supports idempotent operations or handle duplicates accordingly.
• The package depends on connectivity_plus, http, sqflite, and path.

Example #

Here is a simple example that queues a POST request:

await OfflineQueue.instance.post(
  url: 'https://jsonplaceholder.typicode.com/posts',
  headers: {'Content-Type': 'application/json'},
  body: {
  'title': 'Test Post',
  'body': {'content': 'This is a test post', 'author': 'Mohammad'},
  'userId': 1,
  },
);

Contributing #

Contributions are welcome! Feel free to open issues or submit pull requests.

License #

This project is licensed under the MIT License - see the LICENSE file for details.

Contact #

Created by Mohammad AD — feel free to reach out! bummycakes.com - DCP