check-ios-bus/src/App.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate
{
    var window: UIWindow?

    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        let vc = UIViewController()
        addSwiftUIViewAsChild(swiftUIView: V(), parent: vc.view)
        vc.view.backgroundColor = .gray
        window?.rootViewController = vc
        window?.backgroundColor = UIColor.white
        window?.makeKeyAndVisible()

        return true
    }
}

/*
// Bus.Pipe.swift
public extension Bus {
    final class BindingPipe<T: Equatable>: ObservableObject {
        public let input = PassthroughSubject<T, Never>()
        public let output = PassthroughSubject<T, Never>()
        @Published var value: T
        var isInput = false
        var subscriptions = [AnyCancellable]()
        
        deinit {
            print("ИГР BusBP.DEinit(\(Unmanaged.passUnretained(self).toOpaque()))")
        }
        
        init(
            _ defaultValue: T,
            _ keyApp: String,
            _ keyUI: String
        ) {
            value = defaultValue
            /**/dbg("ИГР BusBP.init(\(Unmanaged.passUnretained(self).toOpaque())) keyA: '\(keyApp)'")
            
            // TextField -> output.
            $value
                .sink { [weak self] v in
                    assert(Thread.isMainThread)
                    // Ignore values received from input.
                    // Only accept UI provided values.
                    guard
                        let self,
                        !self.isInput
                    else {
                        return
                    }
                    self.output.send(v)
                }
                .store(in: &subscriptions)
            
            // input -> TextField.
            input
                .sink { [weak self] v in
                    assert(Thread.isMainThread)
                    guard let self else { return }
                    /**/dbg("ИГР BusBP.init input: '\(v)'")
                    self.isInput = true
                    self.value = v 
                    self.isInput = false
                }
                .store(in: &subscriptions)
            
            // Оповещаем в мир об изменениях от UI.
            Bus.sendAsync(
                &subscriptions,
                keyUI,
                output.eraseToAnyPublisher()
            )
            
            Bus.receive(
                &subscriptions,
                [keyApp],
                { [weak self] _, v in
                    self?.input.send(v)
                   /**/print("ИГР BusBP.init receive: '\(v)'")
                }
            )
        }
    }
}

// BusSlot.swift
var busHolder = Bus.Service()

// ========================================
// MARK: - MeetupX module
// ========================================

enum MeetupId {
    enum Keys: String, RawRepresentable {
        case meetupIdTextApp
        case meetupIdTextUI
    }
    
    static func shouldFormat(_ s: String) -> String? {
        return s.components(separatedBy: NSCharacterSet.decimalDigits.inverted).reduce("") { $0 + $1 }
    }
    
    final class MeetupIdFormatter {
        var subscriptions = [AnyCancellable]()

        deinit {
            /**/dbg("ИГР MeetupIF.DEinit")
        }

        init() {
            Bus.receive(
                &subscriptions,
                [Keys.meetupIdTextUI.rawValue],
                { [weak self] k, v in self?.handleFormatting(k, v) }
            )
            /**/dbg("ИГР MeetupIF.init")
        }
        
        func handleFormatting(_: String, _ value: String) {
            let out = MeetupId.shouldFormat(value)
            /**/dbg("ИГР MeetupIF.handleF out/dt: '\(out)'/'\(Date())'")
            Bus.Service.singleton?.send(Keys.meetupIdTextApp.rawValue, out)
        }
    }

    struct V: View {
        /*@StateObject*/ var fmt = MeetupIdFormatter()
        @StateObject var txt = Bus.BindingPipe("", Keys.meetupIdTextApp.rawValue, Keys.meetupIdTextUI.rawValue)
        
        var body: some View {
            VStack {
                Text("Hi, the text is: '\(txt.value)'")
                    .fontWeight(.bold)
                TextField("Placeholder", text: $txt.value)
                    .padding(8)
                    .border(Color.blue, width: 2)
            }
            .frame(width: 320)
            .padding()
        }
    }
}

*/