Book Image

An iOS Developer's Guide to SwiftUI

By : Michele Fadda
Book Image

An iOS Developer's Guide to SwiftUI

By: Michele Fadda

Overview of this book

– SwiftUI transforms Apple Platform app development with intuitive Swift code for seamless UI design. – Explore SwiftUI's declarative programming: define what the app should look like and do, while the OS handles the heavy lifting. – Hands-on approach covers SwiftUI fundamentals and often-omitted parts in introductory guides. – Progress from creating views and modifiers to intricate, responsive UIs and advanced techniques for complex apps. – Focus on new features in asynchronous programming and architecture patterns for efficient, modern app design. – Learn UIKit and SwiftUI integration, plus how to run tests for SwiftUI applications. – Gain confidence to harness SwiftUI's full potential for building professional-grade apps across Apple devices.
Table of Contents (25 chapters)
Free Chapter
1
Part 1: Simple Views
5
Part 2: Scrollable Views
8
Part 3: SwiftUI Navigation
11
Part 4: Graphics and Animation
14
Part 5: App Architecture
17
Part 6: Beyond Basics

What is persistency?

First, let’s define the word persistency. Persistency is the ability of application data to survive between successive runs of an application. As is typical of the Apple ecosystem, there are many ways to achieve persistency of data, and each way has different use cases, advantages, and disadvantages.

If you just store application data in volatile memory – that is, RAM – then data won’t survive across different launches of the same application; each launch would be “a new beginning,” starting from scratch.

Although this approach might suit a handful of specific scenarios, such as projects where there’s no requirement to retain information between launches (e.g., basic utility calculations such as unit conversions), you will need the capability to save data to non-volatile memory in most cases. Furthermore, apart from retrieving it, you’ll often need to perform additional operations. The usual tasks you...