Preface

These recipes cover the most important Flutter features that will allow you to develop real-world apps. In each recipe, you will learn about and immediately use some of the tools that make Flutter so successful: widgets, state management, asynchronous programming, connecting to web services, persisting data, creating animations, using Firebase and machine learning, and developing responsive apps that work on different platforms, including desktop and the web.

Flutter is a developer-friendly, open source toolkit created by Google that you can use to create applications for Android and iOS mobile devices, the web, and desktop.

There are 16 chapters in this book, which you can read independently from one another: each chapter contains recipes that highlight and leverage a single Flutter feature. You can choose to follow the flow of the book or skip to any chapter if you feel confident with the concepts.

Flutter uses Dart as a programming language. Chapter 3, Dart: A Language You Already Know, is an introduction to Dart, its syntax, and its patterns, and it gives you the necessary knowledge to be productive when using Dart in Flutter.

In later chapters, you’ll see recipes that go beyond basic examples; you will be able to play with code and get hands-on experience in using basic, intermediate, and advanced Flutter tools.

Who this book is for

This book is for developers who are familiar with an object-oriented programming language. If you understand concepts such as variables, functions, classes, and objects, this book is for you.

Prior knowledge of Dart is not required as it is introduced in Chapter 3, Dart: A Language You Already Know.

If you already know and use languages such as Java, C#, Swift, Kotlin, and JavaScript, you will find Dart surprisingly easy to learn.

What this book covers

Chapter 1, Getting Started with Flutter, helps you set up your development environment.

Chapter 2, Creating Your First Flutter App, shows how to create your first app, and check that your development environment works as expected.

Chapter 3, Dart: A Language You Already Know, introduces Dart, its syntax, and its patterns.

Chapter 4, Introduction to Widgets, shows how to build simple user interfaces with Flutter.

Chapter 5, Mastering Layout and Taming the Widget Tree, shows how to build more complex screens made of several widgets.

Chapter 6, Adding Interactivity and Navigation to Your app, contains several recipes that add interactivity to your apps, including interacting with buttons, reading a text from a TextField, changing the screen, and showing alerts.

Chapter 7, Basic State Management, introduces the concept of State in Flutter: instead of having screens that just show widgets, you will learn how to build screens that can keep and manage data.

Chapter 8, The Future is Now: Introduction to Asynchronous Programming, contains several examples of one of the most useful and interesting features in programming languages: the concept of the asynchronous execution of tasks.

Chapter 9, Data Persistence and Communicating with the Internet, gives you the tools to connect to web services and persist data on your device.

Chapter 10, Advanced State Management with Streams, shows how to deal with Streams, which are arguably the best tool for creating reactive apps.

Chapter 11, Using Flutter Packages, explains how to choose, use, build, and publish Flutter packages.

Chapter 12, Adding Animations to Your app, gives you the tools you need to build engaging animations in your apps.

Chapter 13, Using Firebase, shows how to leverage a powerful backend without any code.

Chapter 14, Firebase Machine Learning, shows how to add machine learning features to your apps by using Firebase.

Chapter 15, Flutter Web and Desktop, shows you how to use the same code base to build apps for the web and desktop.

Chapter 16, Distributing Your Mobile app, outlines the steps required to publish an app to the main mobile stores: the Google Play Store and the Apple App Store.

To get the most out of this book

Some experience in at least one object-oriented programming language is strongly recommended.

In order to follow along with the code, you will need a Windows PC, Mac, Linux, or Chrome OS machine connected to the web, with at least 8 GB of RAM and the permissions to install new software.

An Android or iOS device is suggested but not necessary as there are simulators/emulators that can run on your machine. All software used in this book is open source or free to use.

Chapter 1, Getting Started with Flutter, explains in detail the installation process; however, you should have the following:

Software/hardware	OS Requirements
Recommended editors: Visual Studio Code, Android Studio, or IntelliJ Idea	Windows, macOS, or Linux
The Flutter SDK	Windows, macOS, or Linux
An emulator/simulator or an iOS or Android device	Windows, macOS, or Linux

In order to create apps for iOS, you will need a Mac.

If you are using the digital version of this book, we advise you to type the code yourself or access the code via the GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

If you like this book or want to share your ideas about it, please write a review on your favorite platform. This will help us make this book better, and you’ll also earn the author’s and reviewers’ everlasting gratitude.

Download the example code files

The code bundle for the book is hosted on GitHub at https://github.com/PacktPublishing/Flutter-Cookbook-Second-Edition/. We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Download the color images

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it here: https://packt.link/WE615.

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. For example: “Add the latest version of the lint package as a dev dependency in your pubspec.yaml, and remove any other linting packages you may find there.”

A block of code is set as follows:

dependencies: 
  flutter: 
    sdk: flutter 
  http: ^0.13.5

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

dev_dependencies: 
  flutter_test: 
    sdk: flutter 
  lint: ^2.0.0

Any command-line input or output is written as follows:

# cp /usr/src/asterisk-addons/configs/cdr_mysql.conf.sample
     /etc/asterisk/cdr_mysql.conf

Bold: Indicates a new term, an important word, or words that you see on the screen. For instance, words in menus or dialog boxes appear in the text like this. For example: “ In order to use Google Maps, you need to obtain an API key.”

Warnings or important notes appear like this.

Tips and tricks appear like this.

Get in touch

Feedback from our readers is always welcome.

General feedback: Email [e-mail] and mention the book’s title in the subject of your message. If you have questions about any aspect of this book, please email us at [e-mail].

Errata: Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you have found a mistake in this book, we would be grateful if you reported this to us. Please visit http://www.packtpub.com/submit-errata, click Submit Errata, and fill in the form.

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