Book Image

Flutter Cookbook

By : Simone Alessandria, Brian Kayfitz
4 (1)
Book Image

Flutter Cookbook

4 (1)
By: Simone Alessandria, Brian Kayfitz

Overview of this book

“Anyone interested in developing Flutter applications for Android or iOS should have a copy of this book on their desk.” – Amazon 5* Review Lauded as the ‘Flutter bible’ for new and experienced mobile app developers, this recipe-based guide will teach you the best practices for robust app development, as well as how to solve cross-platform development issues. From setting up and customizing your development environment to error handling and debugging, The Flutter Cookbook covers the how-tos as well as the principles behind them. As you progress, the recipes in this book will get you up to speed with the main tasks involved in app development, such as user interface and user experience (UI/UX) design, API design, and creating animations. Later chapters will focus on routing, retrieving data from web services, and persisting data locally. A dedicated section also covers Firebase and its machine learning capabilities. The last chapter is specifically designed to help you create apps for the web and desktop (Windows, Mac, and Linux). Throughout the book, you’ll also find recipes that cover the most important features needed to build a cross-platform application, along with insights into running a single codebase on different platforms. By the end of this Flutter book, you’ll be writing and delivering fully functional apps with confidence.
Table of Contents (17 chapters)
About Packt

How it works...

A Completer creates Future objects that can be completed later. The Completer.future that's set in the getNumber method is the Future that will be completed once complete is called.

In the example in this recipe, when you call the getNumber() method, you are returning a Future, by calling the following:

return completer.future;

The getNumber() method also calls the calculate() async function, which waits 5 seconds (here, you could place any long-running task), and calls the completer.complete method.

Completer.complete changes the state of the Completer, so that you can get the returned value in a then() callback. 

 Completers are very useful when you call a service that does not use Futures, and you want to return a Future. It also de-couples the execution of your long-running task from the Future itself.