What is WorkManager ? | Importance of Workmanager in Flutter: When, Why, and Where to Use It ?

WorkManager in Flutter

Workmanager is a powerful tool that allows developers to execute tasks outside of the UI thread in a reliable and consistent way, even when the app is in the background or has been terminated. This makes it an essential tool for performing background tasks in Flutter apps, whether it’s for fetching data, running background jobs, or scheduling alarms.

When to use Workmanager in Flutter?

Workmanager should be used whenever you need to perform a task outside of the UI thread and want to ensure that the task will run even if the app is in the background or has been terminated. For example, you may want to use Workmanager to:

• Fetch data from a server at regular intervals.
• Schedule an alarm to notify the user of an event.
• Run background jobs that take a long time to complete.
• Perform any other task that requires a reliable and consistent execution even when the app is not in the foreground.

Why do we use WorkManager in Flutter?

There are several reasons why should we use Workmanager in our Flutter app:

• Consistency: Workmanager ensures that your tasks are executed in a consistent and reliable way, even if the app has been terminated or the device has been restarted.
• Background execution: Workmanager allows you to perform tasks outside of the UI thread, even when the app is in the background, making it ideal for background tasks like fetching data, running background jobs, and scheduling alarms.
• Easy to use: Workmanager provides a simple and intuitive API that makes it easy to execute tasks in the background.
• Cross-platform: Workmanager is a cross-platform library that supports both Android and iOS, allowing you to write code once and run it on both platforms.

Where to use Workmanager in Flutter?

Workmanager can be used in any Flutter app that requires background execution of tasks. Whether you’re building a simple to-do app, a news aggregator, or a complex enterprise app, Workmanager can help you perform background tasks in a reliable and consistent way.

To use WorkManager in Flutter, you can leverage the workmanager package, which provides a Flutter-friendly interface to interact with the WorkManager APIs.

Here’s an example of how to use WorkManager in Flutter:

Add the workmanager package to your pubspec.yaml file:

dependencies:
  workmanager: ^0.5.0 # use latest version


Note to implement Workmanager you have to mention  @pragma('vm:entry-point')  above method then it will work

Create a Dart file to define your background task

import 'package:workmanager/workmanager.dart';

@pragma('vm:entry-point') // Mandatory 
void callbackDispatcher() {
  Workmanager.executeTask((task, inputData) {
    // Perform your background task here
    print('Background task is running');

    return Future.value(true); // Return a Future indicating success or failure
  });
}

void registerBackgroundTask() {
  Workmanager.initialize(callbackDispatcher);
  Workmanager.registerOneOffTask(
    'myTask', // Task ID
    'myTaskName', // Task Name
    inputData: {}, // Optional input data for the task
  );
}

In your Flutter application, call the registerBackgroundTask() method to register the background task. You can call this method from your main() function or any other suitable place in your application’s lifecycle.

void main() {
  WidgetsFlutterBinding.ensureInitialized();

  registerBackgroundTask();

  runApp(MyApp());
}

Run your Flutter application, and the background task will be scheduled and executed by WorkManager. You can monitor the logs to see the output of the background task.

Note that the behavior of WorkManager may vary on different Android devices and versions. It is primarily designed for Android and may not work on other platforms. Make sure to test and handle platform-specific behaviors accordingly.

You can also refer this example

https://pub.dev/packages/workmanager/example

In conclusion, Workmanager is a powerful tool for performing background tasks in Flutter apps. Its simple API, cross-platform support, and ability to run tasks in the background make it an essential tool for any app that requires background execution. Whether you’re fetching data, running background jobs, or scheduling alarms, Workmanager is the solution you need to ensure your app runs smoothly and consistently, even when it’s not in the foreground.