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)
16
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This recipe also used some Dart language features that you might be unfamiliar with  null-aware operators and null coalescing operators. Let's look more carefully at this line of code:

tasks = model?.data['task']
?.map<Task>((task) => Task.fromModel(task))
?.toList() ?? <Task>[];

When you insert null-aware operators, a ? is inserted after any variable that might be null. Here, you are telling Dart that if this variable is null, then just skip everything after the question mark. In this example, the model property might be null, so if we tried to access the data property on a null, Dart would throw an exception. In this case, if a null is ever encountered, this code will be gracefully skipped.

The null coalescing operator, ??, is used almost like a ternary statement. This operator will return the value on the right-hand side of the question marks if the value on the left-hand side is...