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Making Friends with Asynchronous Programming and Futures in Flutter

Making Friends with Asynchronous Programming and Futures in Flutter

Published: Sun May 14 2023

Let’s dig into the world of asynchronous programming in Flutter! This style of coding is like a magician’s trick—it allows us to perform multiple tasks at the same time without any hiccups. In this article, we’re going to untangle what asynchronous programming is, why it’s a must-know for Flutter devs, and give you a hands-on guide to implement it using Futures. So, buckle up!

Asynchronous Programming: Your New Best Friend

Imagine you’re at a party. You’re trying to juggle conversations with multiple friends, grab some snacks, and keep an eye on the game playing on the TV—all at the same time. That’s what asynchronous programming is like. It lets your Flutter app multitask, running several processes simultaneously without blocking each other. So, while one part of your app is busy fetching data from the internet, the rest of the app can continue to respond to user inputs and keep the party going.

Why Flutter Loves Asynchronous Programming

Just like a good party needs a great host, a smooth and responsive Flutter app needs asynchronous programming. Flutter apps often deal with complex and beautiful UIs full of lively animations. But these animations can be like the party guests who always demand your attention—if handled synchronously, they can make your app freeze or become unresponsive. Asynchronous programming is the art of managing these guests so that everyone can enjoy the party, ensuring your app runs without a hitch.

Hands-On with Futures in Flutter

Let’s dive into Futures—a key player in Flutter’s asynchronous programming. A Future is like a promise: it represents a value that may not be ready right now, but will be in the future. They’re the perfect tool for dealing with tasks that need some time, like making a network request or reading a file.

Let’s see Futures in action:

Future<void> fetchTodo() async {
  try {
    final response = await http.get(Uri.parse(''));
    if (response.statusCode == 200) {
      print('Todo: ${response.body}');
    } else {
      print('Oops! Failed to fetch the todo');
  } catch (e) {
    print('An error occurred: ${e.toString()}');

In this example, we’re making an HTTP GET request to fetch a to-do item from a JSON endpoint using the http package. The await keyword is our magic wand here—it makes the code pause (without blocking the rest of the app) until we get a response back.

Dealing with Errors in Futures

When using Futures, it’s essential to prepare for any uninvited guests—errors. We can handle these party crashers in a couple of ways. One way is using a try-catch block like in the example above. If any error crashes the party, the catch block gently escorts it out and keeps the app from collapsing.

Another approach is using the .then() and .catchError() methods. Here’s how:

Future<String> fetchTodo() async {
  final response = await http.get(Uri.parse(''));

  return response.body;

void main() {
    .then((todo) => print('Todo: $todo'))
    .catchError((error) => print('An error occurred: ${error.toString()}'));

Here, .then() handles the successful completion of fetching the to-do (i.e., the good times), and .catchError() handles any errors (i.e., the party crashers).

Wrapping Up

Asynchronous programming is a crucial skill for Flutter developers, and Futures are the secret sauce in this recipe. By mastering Futures, you can create apps that can multitask efficiently, providing a smooth and responsive experience for users. And remember—always be ready for unexpected errors during your async operations to keep your app running smoothly. Just like a great party, a great app is all about managing different elements harmoniously, ensuring everything flows seamlessly for an enjoyable user experience. Happy coding!

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