Flutter Heyteacher Worker

This package provides a generics Worker<I,O> class to run long-running tasks in a background isolate, preventing the UI from freezing. It simplifies the process of offloading computation from the main thread.

The implementation is based on Robust ports example described in Dart Isolates official documentation.

Features

  • Worker<I, O>: A generics class that manages the lifecycle of a long-running isolate.

Important

The Worker<I, O> will not spawn a real isolate on the web plaftorm or during Flutter tests.

In web and Flutter tests environments, the task will be executed on the main thread instead.

Usage

Import the main library file to access the components:

import 'package:flutter_heyteacher_worker/worker.dart';

To use Worker<I, O>, you need to:

  • define a top-level or static function that matches the signature Future<O> function(I input)
  • pass it to the Worker constructor.

Example

Here is a simple example of how to use the Worker<I, O> to perform a computation in a background isolate.

// 1. Define your worker logic as a top-level or static function.
// This function will be executed in the background isolate.
// `I` is the input type is `String` 
// `O` is the output type is `int`.
Future<int> calculateStringLength(String input) async {
  // Simulate a heavy computation
  await Future.delayed(const Duration(seconds: 1));
  return input.length;
}

Future<void> runWorker() async {
  final worker = Worker<String, int>(calculateStringLength);
  final result = await worker.execute('hello worker');

  print('Result from worker: ${result.output}'); // Result from worker: 12

  worker.close();
}

Libraries

flutter_heyteacher_worker