[Coombine][Publishers] how to use maxPublishers
not sure the following logic will create three publishers? [1,2,3].publisher [1,2,3,4].publisher .flatMap(maxPublishers: .max(1)) { result in change(result) }.sink { result in print(result)...
View Article[Combine]subscribe method
I know publisher has a method subscribe(_ subject: Subject) let arrPublisher = [1,2,3,4].publisher let tester = PassthroughSubject<Int, Never>() arrPublisher.sink { result in print(result)...
View Article[Combine]throttle bug?
let subject = PassthroughSubject<String, Never>() let throttled = subject.throttle(for: .seconds(10), scheduler: DispatchQueue.main, latest: false) throttled.sink(receiveValue: {print($0,...
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Chapter 15.9 EnvironmentObject usage
Here is the moment at the end of the chapter, that describes “you need to add EnvironmentObject to ReaderView”: One as a property - @EnvironmentObject var settings: Settings Second as pass param to...
View ArticleChap 2: Understanding what's going on
Under the above heading you explain: 3. A subscriber calls subscribe(_:) on a publisher to attach to it. 4. The implementation of subscribe(_:) will call receive(subscriber:) to attach the subscriber...
View ArticleDebounce unit test
Hello, Let’s suppose we have a a string as a published property in our view model. We subscribe to this published property in our view model and use different combine operators. One of these operators...
View ArticleChapter 14.3: Complexity vs easier alternative?
When I first read the task for mergedStories I initially thought about using a flatMap and wondered about the complexity used in that function (creating array, remainder, merge). So I tried a...
View ArticleChapter 15: Lots of warnings
I’m following the text, adding to the starter/HNReader.xcodeproj Looking for the first numbers to appear when adding .onAppear method, I find my debug output cluttered with lots of warnings (I’m on...
View ArticleChapter 18: Purpose of .max(1)
In chapter 18, when defining the DispatchTimerSubscription you use self.requested -= .max(1) self.timer -= .max(1) and I wonder what .max(1) actually does and why it’s needed. I imaging it creates a...
View ArticleWhy do publishers subscribe instead of subscribers?
Hello, Could someone please help me understand why linguistically a publisher connects to a subscriber instead of the other way around? For example in Chapter 2: Custom Subscriber, we do: let...
View ArticleQuestion for Combine: Asynchronous Programming with Swift
Hello I am studying Combine with the book, and I have questions on Chapter 18. There is a description like below, and I can not understand what it means. Specifically on bold text. Use the handy...
View ArticleCharter 18 error: Publisher is only available in iOS 13.0
‘Publisher’ is only available in iOS 13.0 or newer extension Publisher { help me please 3 posts - 3 participants Read full topic
View ArticleChild view-models state management with SwiftUI and Combine
This is more of an opinion/architecture question, with questions that arose out of chapter 15 from the Combine + SwiftUI book. I have a rather larger screen that I am building with SwiftUI and...
View ArticleWhat is different between Async/Await, Combine, Closures?
Hello Kodeco team, Like the question in the title, I really wonder why apple built so many solutions for concurrency? difference between them? When should it apply? nghiaphamsg 3 posts - 2...
View ArticleHow KVO options really works (.old and .new)?
I don’t understand how .old and .new options work. Would anyone have an example to show? 1 post - 1 participant Read full topic
View ArticleErrata for Combine: Asynchronous Programming With Swift 4th Edition
Creating this topic to catch any typos and bugs in the 4th Edition of Combine: Asynchronous Programming With Swift. 2 posts - 1 participant Read full topic
View ArticleChapter 18, Custom Publisher & Ownership
When creating a custom publisher, you also create a custom subscription. In the book ShareReplay example, the ShareReplay subscription owns a reference to the subscriber, but I don’t see that it holds...
View ArticleHow do i observe an Array when append or remove element with Combine?
When I adding or removing element in names array, no any result. following the code. Could you give and advice? class SomeClass: NSObject { @objc var names = ["A", "B", "C"] var cancellable:...
View ArticleChapter 2: Question about notification
I do a simple notification test with combine. Click postNotification button in ViewController that received notification successful. Click removeReceiver button (set _receive to nil) in ViewController...
View ArticleChapter 2: error when I try to run playground
I see the following error at the top of xcode when I try to run the playground: Failed to launch process. Failed to compile sandbox profile: sandbox_extension_issue_file: Operation not permitted I get...
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Spelling Error Chapter 20
Hi There - Noticed that SwiftUI is missing an ‘I’ character in this note. 3 posts - 2 participants Read full topic
View ArticleAre there more book updates coming?
Hi, The last version of this book was Jul 19, 2023 · iOS 16, Swift 5.8, Xcode 14. Just wondering if this will be updated for iOS 17 / 18 or is another book being created? Thanks. 2 posts - 2...
View ArticleHow to use @Observable to publish a class' properties
I have tried to modify ColorCalc in chapter 19 to use @Observable for the CalculatorViewModel. There were several issues which I could not solve. Can no longer use @Published for properties. Cannot...
View ArticleChapter 2: Bridging Combine Publishers to async/await
Why does this code snippet produces different results? example(of: "async/await") { let subject = CurrentValueSubject<Int, Never>(0) Task { for await element in subject.values { print("Element:...
View ArticleChapter 4. Finding Values `last(where:)`
example(of: "last(where:)") { enum MyError: Error { case test } let subject = PassthroughSubject<Int, MyError>() subject .eraseToAnyPublisher() .last(where: { $0 % 2 == 0 })...
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