ViewController.swift

import UIKit
import Combine

...

enum State: String {
    case initial = "Initial"
    case loading = "Loading"
    case loadedSuccessfully = "Success"
    case loadingFailed = "Failure"
}

class ViewController: UIViewController {

    ...
    
    @Published var state: State = .initial
    
    override func viewDidLoad() {
        ...
        
    }
    
    private func bindAvatarToImageView() {
        getAvatarFromTheServer()
            .handleEvents(receiveSubscription: { [weak self] in
                print("Subscribed", $0)
                
                // 1
                self?.state = .loading
            }, receiveOutput: {
                ...
            }, receiveCompletion: {
                ...
            })
            .delay(...)
            .retry(...)
            .receive(...)
            .sink(receiveCompletion: { [weak self] completion in
                switch completion {
                case let .failure(error):
                    print("Finished with error: \(error)")
                    
                    // 2
                    self?.state = .loadingFailed
                case .finished:
                    print("Finished")
                }
            }, receiveValue: { [weak self] image in
                self?.imageView.image = image
                
                // 3
                self?.state = .loadedSuccessfully
            })
            .store(in: &cancellables)
    }
    
    private func getAvatarFromTheServer() -> AnyPublisher<UIImage, Error> {
      ...
    }

}