Book Image

Swift Cookbook. - Second Edition

By : Keith Moon, Chris Barker

Book Image

Swift Cookbook. - Second Edition

By: Keith Moon, Chris Barker

Overview of this book

Swift is an exciting, multi-platform, general-purpose programming language, and with this book, you'll explore the features of its latest version, Swift 5.3. The book begins with an introduction to the basic building blocks of Swift 5.3, its syntax, and the functionalities of Swift constructs. You’ll then discover how Swift Playgrounds provide an ideal platform to write, execute, and debug your Swift code. As you advance through the chapters, the book will show you how to bundle variables into tuples or sets, order your data with an array, store key-value pairs with dictionaries, and use property observers. You’ll also get to grips with the decision-making and control structures in Swift, examine advanced features such as generics and operators, and explore functionalities outside of the standard library. Once you’ve learned how to build iOS applications using UIKit, you'll find out how to use Swift for server-side programming, run Swift on Linux, and investigate Vapor. Finally, you'll discover some of the newest features of Swift 5.3 using SwiftUI and Combine to build adaptive and reactive applications, and find out how to use Swift to build and integrate machine learning models along with Apple’s Vision Framework. By the end of this Swift book, you'll have discovered solutions to boost your productivity while developing code using Swift 5.3.

Preface

Who this book is for

What this book covers

To get the most out of this book

Swift Building Blocks

Swift Building Blocks

Technical requirements

Creating your first Swift program

Using Strings, Ints, Floats, and Bools

Unwrapping optionals, and force unwrapping

Reusing code in functions

Encapsulating functionality in object classes

Bundling values into structs

Enumerating values with enums

Passing around functionality with closures

Using protocols to define interfaces

Free Chapter

Mastering the Building Blocks

Mastering the Building Blocks

Technical requirements

Bundling variables into tuples

Ordering your data with arrays

Containing your data in sets

Storing key-value pairs with dictionaries

Subscripts for custom types

Changing your name with typealias

Getting property changing notifications using property observers

Extending functionality with extensions

Controlling access with access control

Data Wrangling with Swift Control Flow

Data Wrangling with Swift Control Flow

Technical requirements

Making decisions with if/else

Handling all cases with switch

Looping with for loops

Looping with while loops

Handling errors with try, throw, do, and catch

Checking upfront with guard

Doing it later with defer

Bailing out with fatalError and precondition

Generics, Operators, and Nested Types

Generics, Operators, and Nested Types

Technical requirements

Using generics with types

Using generics with functions

Using generics with protocols

Using advanced operators

Defining option sets

Creating custom operators

Nesting types and namespacing

Beyond the Standard Library

Beyond the Standard Library

Technical requirements

Comparing dates with Foundation

Fetching data with URLSession

Working with JSON

Working with XML

Building iOS Apps with Swift

Building iOS Apps with Swift

Technical requirements

Building an iOS App using Cocoa Touch

Unit and integration testing with XCTest

User interface testing with XCUITest

Backward compatibility

Swift Playgrounds

Swift Playgrounds

Technical requirements

Using Swift Playgrounds for UI

Importing resources into playgrounds

Importing code into playgrounds

Multi-page playgrounds

Using Swift Playgrounds on iPadOS

Server-Side Swift

Server-Side Swift

Technical requirements

Running Swift on Linux

Building a REST API using Vapor and Fluent

Database persistence with Fluent and Postgres

Hosting your Vapor app on Heroku

The Swift Package Manager

Real-time communication using WebSockets

Packaging and sharing models between server and app

Performance and Responsiveness in Swift

Performance and Responsiveness in Swift

Technical requirements

Value and reference semantics

Using Dispatch queues for concurrency

Concurrent queues and dispatch groups

Implementing the operation class

SwiftUI and Combine Framework

SwiftUI and Combine Framework

Technical requirements

Declarative syntax

Function builders, property wrappers, and opaque return types

Building simple views in SwiftUI

Combine and data flow in SwiftUI

Using CoreML and Vision in Swift

Using CoreML and Vision in Swift

Technical requirements

Building an image capture app

Using CoreML models to detect objects in images

Building a video capture app

Using CoreML and the Vision Framework to detect objects in real time

About Packt

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Importing code into playgrounds

As we have seen throughout this chapter, and this book, playgrounds are a great canvas for exploring APIs, frameworks, and custom code. However, if you want to explore uses for your own code, it appears that you need to include all the code needed in the playground, and that can make it long and unwieldy.

It doesn't need to be that way. In this recipe, we will see how you can embed Swift code in your playground and make use of it from your playground code.

Getting ready

For this recipe, we will use the playground from the previous recipe, called EmbeddedResources.playground, which can be retrieved from this book's GitHub repository at https://github.com/PacktPublishing/Swift-Cookbook-Second-Edition/tree/master/Chapter07/02_Import_Resources_into_Playgrounds.

How to do it...

We will take the BarChart custom view and related code and move it to a separate file embedded within the playground, leaving us free to use the playground to experiment with...