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)

Chapter 13: Handling Core Data in SwiftUI

Core Data is one of the most essential Apple frameworks in the iOS and macOS ecosystem. Core Data provides persistence, which means it can save data outside the app's memory, and the data you save can be retrieved after you restart your app. Given its importance, it's not a surprise that Apple has implemented some extensions for Core Data to make it work nicely with SwiftUI.

In Core Data language, a stored object is an instance of NSManagedObject, which conforms to the ObservableObject protocol so that it can be observed directly by a SwiftUI's view.

Also, NSManagedObjectContext is injected into the environment of the View's hierarchy so that SwiftUI's View can access it to read and change its managed objects.

A very common feature of Core Data is that you can fetch objects from its repository. For this purpose, SwiftUI provides the @FetchRequest property wrapper, which can be used in a view to load data.

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