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SwiftUI Projects

You're reading from   SwiftUI Projects Build six real-world, cross-platform mobile applications using Swift, Xcode 12, and SwiftUI

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Product type Paperback
Published in Dec 2020
Publisher Packt
ISBN-13 9781839214660
Length 410 pages
Edition 1st Edition
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Author (1):
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Craig Clayton Craig Clayton
Author Profile Icon Craig Clayton
Craig Clayton
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Table of Contents (13) Chapters Close

Preface 1. Chapter 1: SwiftUI Basics 2. Chapter 2: SwiftUI Watch Tour FREE CHAPTER 3. Chapter 3: NBA Draft – Watch App 4. Chapter 4: Car Order Form – Design 5. Chapter 5: Car Order Form – Data 6. Chapter 6: Financial App – Design 7. Chapter 7: Financial App – Core Data 8. Chapter 8: Shoe Point of Sale System – Design 9. Chapter 9: Shoe Point of Sale System – CloudKit 10. Chapter 10: Sports News App – Design 11. Chapter 11: Sports News App – Data 12. Other Books You May Enjoy

SwiftUI and Core Data optionals

If you have used Swift before, you are familiar with Optionals, but it is handled much differently when it comes to Core Data. If you uncheck the Optional checkbox in Attributes inspector, it will still be generated as an optional Swift property. Core Data only cares that properties have values when saved and can be nil at other times. There are different ways to handle this, but I found the most elegant way was to create an extension in the Optional class. If you look inside the Utilities folder, you will see three files — IntOptional.swift, BoolOptional.swift, and StringOptional.swift. Each of these files is structured the same way, but they work for Int, Boolean, and String, respectively.

Let's look at StringOptional.swift in a little more detail using the following code:

Figure 7.12

Now with this file, we can make our code a bit shorter:

  1. We do not have to do something like this in our code:
    Image(self...
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