peterfriese/asynchronous-programming-with-swiftui-and-combine

Code for my book, SwiftUI & Combine

Hi, I'm Peter 👋🏼

I'm a Developer Advocate (which is just a fancy word for "Software Engineer who loves to tinker around with technology and teach other people") on the Firebase team 🔥.

My recent posts on peterfriese.dev

• Styling SwiftUI Views
• Previewing Stateful SwiftUI Views
• Asynchronous programming with SwiftUI and Combine
• Building a Custom Combine Operator for Exponential Backoff
• Error Handling with Combine and SwiftUI

My recent videos

• I talked to ChatGPT for 1.5hrs and all I got was a lousy todo list app
• SwiftUI: Packaging Views
• SwiftUI: Custom Validation Handling
• SwiftUI: Exposing a View's State
• Swift Concurrency Essentials: Task Cancellation

My recent Firebase videos

• Adding Firebase to your app with SPM #shorts
• Delete user accounts and their data
• Fetch data from Firestore with one line of code
• Happy Holidays from the Firebase team! #FirebaseUnwrapped
• Getting started with Cloud Firestore on Apple platforms

Find me around the web 🌎

• Answering your SwiftUI & Firebase questions on StackOverflow 📚
• Writing about stuff I built on my blog, peterfriese.dev ✒️
• Talking all things Firebase 🔥 and Swift 🍏 on YouTube: @peterfriese
• Chatting away on Twitter: @peterfriese 🐦
• Oh, yeah - and of course, I am now on Mastodon: @[email protected]

asynchronous-programming-with-swiftui-and-combine's Issues

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 56

What is wrong

Text("367 pages")

What's the correct spelling

Text("451 pages")

Solutions to exercises for each chapter?

Right now the repository only has the code in the book but not the code for exercise. What is the best way to check if you have done it correctly?

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 54

What is wrong

Figure 2-11 uses a different book name and page numbers than the original list cell. May be confusing to some users.

What's the correct spelling

1. Title should be "Asynchronous Programming with SwiftUI and Combine" instead of "SwiftUI and Combine"
2. 367 pages should be 451 pages

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 185

What is wrong

class BooksViewModel: ObservableObject {
@published var books: [Book] = Book.samples
}

What's the correct spelling

"Book.samples" should be "Book.sampleBooks"

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 48

What is wrong

"To insert an image to the left of the two Text views"

What's the correct spelling

"To insert an image to the left of the three Text views"

[TYPO] Page 28, Missing modifiers in code snippet

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 28

What is wrong

In the code snippet the modifiers .font(.title) and .foregroundColor(Color.pink) are missing.

What's the correct spelling

The modifiers .font(.title) and .foregroundColor(Color.pink) should still modify the Text element.

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 96

What is wrong

@State var name = "Peter"
...
TextField("Enter your name", text: $title)
Text("Hello (title), nice to meet you!")

What's the correct spelling

$title should be $name
(title) should be name

Hyphen in Github URL.

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page:

What is wrong

There's a hyphen between Peter and Friese "Peter-friese" in a hyperlink. It's the first reference to the Github repository. A later reference to the repository in the same chapters footnotes is correct. See attached image.

What is 'async' in this context?

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 390

What is wrong

Was 'async' an early spelling for 'Task'?

What's the correct spelling

Async should be replaced with Task.

[TYPO] Page 23, Text("Tap me") instead of "Tab me"

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 23

What is wrong

Click the Content placeholder (or press the Tab key), and replace it with the following text: Text("Tap me").

What's the correct spelling

Click the Content placeholder (or press the Tab key), and replace it with the following text: "Tap me".

Remark

In the code snippet below it is correct.

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 58

What is wrong

"367 pages"

What's the correct spelling

"451 pages"

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 129

What is wrong

Thanks to SwiftUI’s declarative syntax, adding animations to make this
feel more natural is super easy: all we need to do is adding an animation
view modifier to the List view:

What's the correct spelling

Change "adding" to "add"

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 230

What is wrong

Whenever one of the published properties changes, the view
model will emit the changes values, telling SwiftUI to update all affected views.

What's the correct spelling

"changes values" to "changed values"

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 57

What is wrong

The code BookShelfApptoContentView(books: sampleBooks) needs to be...

What's the correct spelling

BookShelfApptoContentView(books: Book.sampleBooks)

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 70

What is wrong

"In addition to using these views in your own app, you can make them
reusable by extracting them into s Swift package."

What's the correct spelling

"into s" should be "into a"?

Missing await in code example:

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 387

What is wrong

Missing 'await' in code sample

What's the correct spelling

Add await.

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 126

What is wrong

One of the most common ways to let users refresh data is pull-to-refresh, made popular in. 2008 by Loren Brichter in the Tweetie app (later acquired by Twitter and relaunched as Twitter for iOS).

What's the correct spelling

Remove the period between in and 2008

[TYPO]

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 57

What is wrong

Fix the compiler errors by updating the call to
ContentView() both in the preview and in
BookShelfApp to ContentView(books: sampleBooks)

What's the correct spelling

sampleBooks should be Book.sampleBooks otherwise you get the error: Cannot find 'sampleBooks' in scope

Dated references

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: a few different places

What is wrong

Book mentions Xcode 13 betas in times of Xcode 14.2. It also mentions 'new in Swift 5.5' which is not wrong, but perhaps also not new in times of 5.7..

What's the correct spelling

Not easy to suggest an update here...

[TYPO] Chapter 4. State Management - wrong variable used

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: Chapter 4 - under heading "Binding Value Types"

What is wrong

The variable name is not correct in the Hello World example on @State bindings

https://imgur.com/a/naXDSYZ

What's the correct spelling

The variable should be consistent throughout the example

[TYPO] Page 62, Using the name BookRowView without changing the name of ExtractedView

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 62

What is wrong

After extracting the view, it is references with the name BookRowView even though we haven't changed the name of the view yet:

• Inside BookRowView, declare a new property named book of type Book.

What's the correct spelling

ExtractedView

[TYPO] Page 36, id missing in Book struct

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 36

What is wrong

In the code from the Github repo the Book struct already has an id property. This is missing in the code snippet in the book.

What's the correct spelling

The code in the book reflects the code in the repo.

[TYPO] - On page 58

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 58

What is wrong

To do so, just delete the line previewLayout(.sizeThaFits).

What's the correct spelling

.sizeThatFits

[TYPO] Page 11, `Life Cycle: SwiftUI App`

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 11

What is wrong

There is no options Life Cycle: SwiftUI App in Xcode template.

What's the correct spelling

Remove Life Cycle: SwiftUI App

Chapter 2, Book is already Identifiable in the starter project

Describe the bug
The book describes on page 57 how to make the Book type identifiable. But in the starter project the Book struct already is Identifiable.

To Reproduce
Steps to reproduce the behavior:

1. Download the book code repo
2. Open the starter project of Chapter 2
3. Navigate to Book.swift

Expected behavior
Book is not Identifiable. There is no id property

feature request: Add exercises to each chapter

Only Chapters 1, 2, 8, and 9 have exercises. The book would have a greater impact if there were exercises at the end of every chapter

Using Combine when async/await would likely be more readable

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 290

What is wrong

The sample shows a sequence of steps as a chain of reactive operations where async/await would be just fine for the job.

What's the correct spelling

Complicated, since async/await hasn't been discussed yet at this point in the book. Perhaps refer to future chapter and revisit the example later?

[TYPO] Page 57, `Book.` missing in the call to `sampleBooks`

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 57

What is wrong

ContentView(books: sampleBooks)

What's the correct spelling

ContentView(books: Book.sampleBooks)

Literal initializers should not be called directly.

I found a typo in Asynchronous Programming 
with SwiftUI and Combine.

• Edition: 1st
• Page: 313

What is wrong

init(integerLiteral:) is part of the compiler glue to support literals in swift. The documentation states that those initializers should not be called directly.

What's the correct spelling

Not actually certain, but there must be some other way of achieving the same. 😊