RxSwift: Reactive Programming with Swift

This section tells you a few things you need to know before you get started, such as what you’ll need for hardware and software, where to find the project files for this book, and more.

In this part of the book, you’re going to learn about the basics of RxSwift. You are going to have a look at what kinds of asynchronous programming problems RxSwift addresses, and what kind of solutions it offers.

Further, you will learn about the few basic classes that allow you to create and observe event sequences, which are the foundation of the Rx framework.

You are going to start slow by learning about the basics and a little bit of theory. Please don’t skip these chapters! This will allow you to make good progress in the following sections when things get more complex.

Operators are the building blocks of Rx, which you can use to transform, process, and react to events emitted by observables.

Just as you can combine simple arithmetic operators like +, -, and / to create complex math expressions, you can chain and compose together Rx’s simple operators to express complex app logic.

In this section, you will:

• Start by looking into filtering operators, which allow you to process some events but ignore others.
• Move on to transforming operators, which allow you to create and express complex data transformations. You can for example start with a button event, transform that into some kind of input, process that and return some output to show in the app UI.
• Look into combining operators, which allow for powerful composition of most other operators.
• Explore operators that allow you to do time based processing: delaying events, grouping events over periods of time, and more. Work though all the chapters, and by the end of this section you’ll be able to write simple RxSwift apps!

Since Rx is a multi-platform framework, it doesn’t make any assumptions on which device your Rx powered app is running. RxSwift closely follows the general API design that RxPython, RxRuby, RxJS, and all other platforms conform to, so it does not include any specific features or integrations with UIKit or Cocoa to aid you in developing for iOS or macOS.

RxCocoa is a standalone library (though it’s bundled with RxSwift) that allows you to use many prebuilt features to integrate better with UIKit and Cocoa.

RxCocoa will provide you with out-of-the-box classes to do reactive networking, react to user interactions, bind data models to UI controls, and more.

Once you start writing complete apps with RxSwift and RxCocoa, you will also need to take care of more intermediate topics than simply observing for events and processing them with Rx.

In a full production-quality app, you will need to build an error handling strategy, do more advanced multi-threading processing, create a solid test suite, and more.

In this part of the book, you will work through four challenging chapters, which will lift your Rx status from a rookie level to a battle-tested warrior.

RxSwift’s popularity keeps growing every day. Thanks to the friendly and creative community that formed around this library, a lot of community-driven Rx projects are being released on GitHub.

The advantage of the community-built libraries that use RxSwift is that unlike the main repository, which needs to follow the Rx standard, these libraries can afford to experiment and explore different approaches, provide non multi-platform specializations, and more.

In this section you are going to look into just a few of the many community open source projects. The section contains five short cookbook-style chapters that look briefly into five community projects that help you with binding table views, handling user gestures, debugging your observables using RxTimelane, and talking to your server with Alamofire.

The “easy” part of the book is over. :] If you made it this far and are looking to learn even more in order to start creating production apps with RxSwift, this section is for you.

The two chapters in this section are going to help you learn how to build real-life applications with RxSwift.

The first chapter will cover the MVVM application architecture and show how a well designed ViewModel can power both the iOS and macOS versions of an app. You will look into building a flexible networking layer and touch on writing tests for your view models.

The second chapter, and the last one in this book, is going to build upon what you learned about the MVVM architecture and expand on it by adding services into the mix and scene-based navigation.

Once you finish working through this section, you will be one of the top RxSwift developers out there. There is, of course, more to know about Rx but at this point you will be able to figure out things further on your own.

Also, don’t forget to give back to the community! It would not have been possible for us to put this book together without all the amazing Rx folks sharing their knowledge, code, and good vibes.