Technical requirements

In this chapter, we will create, build, and run a Flutter application. The first step is to set up your system so that it can do this.Specifically, you will need to set up your system so that it has the following:

• The latest stable Flutter software development kit (SDK) installed and added to your path
• An integrated development environment (IDE) where you can view and edit Flutter code

Additionally, to run Flutter on a specific platform, there are certain requirements:

• For web, you only need a web browser. This is why developing on web is a great way to start your Flutter journey.
• For Android you will need to install Android Studio which includes the relevant Android emulators
• For iOS you will need to run your development on a Mac and install Xcode which includes the relevant iOS simulators.

The chapter will give you some guidance on how to set up your system, but as you will discover, the Flutter documentation is excellent and includes very accurate and up...

What is Flutter?

Since the advent of the Apple App Store (and subsequently, the Google Play Store), there has been a way for organizations to share programs with mobile users in a very controlled and managed way. Much like websites on the internet, mobile apps have proliferated to encompass all aspects of our lives. And much like websites, over the years, developers have iteratively discovered and learned the best ways to create reliable, scalable, and intuitive mobile apps.As developers have learned to work within the mobile ecosystem, they have followed similar design patterns and framework ideas that were created to deal with the web ecosystem. Much like the complications of developing code for multiple browsers on the web, in the mobile ecosystem, there has been the challenge of developing code that can work on both iOS and Android devices, with the dream always being to have one code base that works across all devices, and even the web.Flutter is a framework that is the culmination...

Hello Flutter – a first glimpse of Flutter

It’s about time we started getting our hands dirty with some code. Over the course of this book, we will create an app where users can record information about their travels with a football club, such as quality of food, view of the pitch, and transportation links. We will start working on this app in earnest in Chapter 5, Building Your User Interface through Widgets. However, before we start on that, Flutter comes with a simple Hello World app that we will get running and then investigate. First of all, though, we need to get your system ready for some Flutter action!. First of all, though, we need to get your system ready for some Flutter action!

Widgets, widgets, everywhere

Flutter widgets are a core part of the framework and are used constantly throughout your code. You will hear the saying “Everything is a widget,” and that is almost true in Flutter. In this section, we will see how Flutter renders the user interface and then how Flutter applies the widgets idea to app development to create awesome UIs.Widgets can be understood as the visual (but not only that) representation of parts of the application. Many widgets are put together to compose the UI of an application. Imagine it as a puzzle in which you define the pieces.Widgets intend to provide a way for your application to be modular, scalable, and expressive with less code and without imposing limitations. The main characteristics of the widgets UI in Flutter are composability and immutability.

Building and running Flutter

The way an application is built is fundamental to how it will perform on the target platform. This is an important step regarding performance. Even though you do not necessarily need to know this for every kind of application, knowing how the application is built helps you understand and measure possible improvements.As we have already pointed out, Flutter relies on the AOT compilation of Dart for release mode and the JIT compilation of Dart for development/debug mode. Dart is one of only a few languages that are capable of being compiled to both AOT and JIT, and Flutter makes the most of this advantage. Let’s look at the different build options available, why you should use each one, and how the capabilities of Dart lead to an optimal developer and user experience.

Summary

In this chapter, we started playing with the Flutter framework. First, we learned some important concepts about Flutter, mainly the concepts of widgets. We saw that widgets are the central part of the Flutter world. This is because the widget concept is everywhere, from rendering performance to the final result on the screen.We also saw how to start a Flutter application project with the framework tools, the basic project structure of files, and the peculiarities of the pubspec.yaml file. We also started exploring the main.dart file, our first foray into the world of Dart coding. In the end, we saw how to run a project on an emulator or simulator.In the next chapter, we will dive deeper into Dart. You had a sneak peek when we looked at widgets, and you saw how similar it is to other common programming languages, such as Java, C#, and Swift. Dart is a great language, and I must confess it is my favorite language to work with. Hopefully, you will share some of this love by the end...

Questions

At the end of each chapter, you’ll find a set of questions like the ones in this section. These will focus on key pieces of information shared within each chapter to ensure you have retained the relevant knowledge.If you are unable to answer any questions, then look back through this chapter for the relevant answers to refresh your knowledge:

1. Which programming language is used for Flutter apps?
2. Which company is the predominant backer of Flutter?
3. What are the two types of compilation available in Dart?
4. Which platforms does Flutter support for production ready applications?
5. What is the tool that checks your Flutter setup is correct?
6. Which command will generate a new Flutter project?
7. What is the purpose of the pubspec.yaml file?
8. Name the three build modes available when building a Flutter app.