Chapter 8 Challenge #1

📚 Official Books Combine: Asynchronous Programming with Swift
1

I was able to have this sort of working with this code:

newPhotos
    .ignoreOutput()
    .filter { [unowned self] _ in
        self.images.value.count == 6
    }
    .sink(receiveCompletion: { [unowned self] _ in
        self.alert(title: "Limit reached", text: "Buy CollagePro to make collages with more than 6 photos")
            .sink(receiveCompletion: { [weak self] _ in
                self?.navigationController?.popToRootViewController(animated: true)
            }, receiveValue: { _ in })
            .store(in: &self.subscriptions)
    }, receiveValue: { _ in
    })
    .store(in: &self.subscriptions)

Anyway the alert shows up when the user manually pops to root view controller via navigation bar.

2

@vale_cocoa Thank you for sharing your solution - much appreciated! :]