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


In the first example, we used the map function. map expects you to take the data element as the input of your function and then transform it into something else. It is very common to map some JSON data that your app received from an API to a strongly typed Dart object:

// Without the map function, we would usually write
// code like this
names = <Name>[];
for (Map rawName in data) {
final first = rawName['first'];
final last = rawName['last'];
final name = Name(first, last);

// But instead it can be simplified and it can
// actually be more performant on more complex data
final names =<Name>((Map rawName) {
final first = rawName['first'];
final last = rawName['last'];
return Name(first, last);

Both samples achieve the same result. In the first option, you create a list that will hold the names. Then, you iterate through each entry in the data list, extract the elements from Map, initialize a named object, and then add it to the list.

The second option is certainly easier for the developer. Iterating and adding are delegated to the map function. All you need to do is tell the map function how you want to transform the element. In this case, the transformation was extracting the values and returning a Name object. map is also a generic function. Consequently, you can add some typing information  in this case, <Name> – to tell Dart that you want to save a list of names, not a list of dynamics.

This example is also purposefully verbose, although you could simplify it even more:

final names =<Name>(
(raw) => Name(raw['first'], raw['last']),

This may not seem like a big deal for this simple example, but when you need to parse complex graphs of data, these techniques can save you a lot of work and time.