Book Image

SwiftUI Cookbook

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI is an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, right from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based book, you’ll work with SwiftUI and explore a range of essential techniques and concepts that will help you through the development process. The recipes cover the foundations of SwiftUI as well as the new SwiftUI 2.0 features introduced in iOS 14. Other recipes will help you to make some of the new SwiftUI 2.0 components backward-compatible with iOS 13, such as the Map View or the Sign in with Apple View. The cookbook begins by explaining how to use basic SwiftUI components. Then, you’ll learn the core concepts of UI development such as Views, Controls, Lists, and ScrollViews using practical implementation in Swift. By learning drawings, built-in shapes, and adding animations and transitions, you’ll discover how to add useful features to the SwiftUI. When you’re ready, you’ll understand how to integrate SwiftUI with exciting new components in the Apple development ecosystem, such as Combine for managing events and Core Data for managing app data. Finally, you’ll write iOS, macOS, and watchOS apps while sharing the same SwiftUI codebase. By the end of this SwiftUI book, you'll have discovered a range of simple, direct solutions to common problems found in building SwiftUI apps.
Table of Contents (15 chapters)

Validating a form using Combine

Sometimes, the reactive way of thinking feels academic and not connected to the usual problems a developer has to solve. In reality, most of the programs we usually write would benefit from using reactive programming, but some problems fit better than others.

Let's consider as an example a part of an app where the user has to fill in a form. The form has several fields, each one with a different way of being validated; some can be validated on their own while others have validation depending on different fields, and all together concur to validate the whole form.

In the imperative way, this turns out to usually create a mess of spaghetti code, but switching to the reactive declarative way, the code becomes really natural.

In this recipe, we'll implement a simple signup page with a username text field and two password fields, one for the password and the other for password confirmation.

The username has a minimum number of characters...