Book Image

SwiftUI Cookbook - Second Edition

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook - Second Edition

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI provides an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based cookbook, you’ll cover the foundations of SwiftUI as well as the new SwiftUI 3 features introduced in iOS 15 and explore a range of essential techniques and concepts that will help you through the development process. The cookbook begins by explaining how to use basic SwiftUI components. Once you’ve learned the core concepts of UI development, such as Views, Controls, Lists, and ScrollViews, using practical implementations in Swift, you'll advance to adding useful features to SwiftUI using drawings, built-in shapes, animations, and transitions. 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 by 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 encountered when building SwiftUI apps.
Table of Contents (17 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.

As an example, let's consider 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 that depends on different fields, and all together concur to validate the whole form.

Imperatively, this usually creates a mess of spaghetti code, but by switching to the reactive declarative way, the code becomes 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, and the password...