SwiftUI with UIViewController Design Pattern.

safariview.swift

import SwiftUI
import SafariServices

struct DemoView: View, Hostable {
    @EnvironmentObject var hostedObject: HostingObject<DemoView>
    
    var address: String = "https://example.com"
    
    func present() { // UIKit code
        let safari = SFSafariViewController(url: URL(string: address)!)
        hostedObject.viewController?.present(safari, animated: true)
    }
    
    var body: some View {
        Button(address, action: present)
    }
}

struct ContentView: View {
    var body: some View {
        DemoView().hosting()
    }
}

///=======

protocol Hostable: View {
    associatedtype Content: View
    var hostedObject: HostingObject<Self> { get }
    func hosting() -> Content
}

extension Hostable {
    func hosting() -> some View {
        HostingObjectView(rootView: self)
    }
}

class HostingObject<ViewType: View>: ObservableObject {
    @Published var viewController: UIViewController? = nil
}

struct HostingObjectView<Content: View>: View {
    var rootView: Content
    
    var hostedObject = HostingObject<Content>()
    
    func getHost(viewController: UIViewController) {
        hostedObject.viewController = viewController.parent
    }
    
    var body: some View {
        Group {
            rootView
        }
        .uiViewController(didAppear: getHost(viewController:))
        .environmentObject(hostedObject)
    }
}

extension View {
    func uiViewController(didAppear: @escaping (UIViewController) -> ()) -> some View {
        modifier(UIViewControllerViewModifier(didAppear:didAppear))
    }
}

struct UIViewControllerViewModifier: ViewModifier {
    var didAppear: (UIViewController) -> Void
    func body(content: Content) -> some View {
        content.background( UIViewControllerView(didAppear: didAppear) )
    }
}

struct UIViewControllerView: UIViewControllerRepresentable {
    final class ViewController: UIViewController {
        var didAppear: (UIViewController) -> Void = { _ in }
        override func viewDidAppear(_ animated: Bool) {
            super.viewDidAppear(animated)
            didAppear(self)
        }
    }
    
    var didAppear: (UIViewController) -> Void
    
    func makeUIViewController(context: Context) -> UIViewController {
        let viewController = ViewController()
        viewController.didAppear = didAppear
        return viewController
    }
    
    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
        //
    }
}

import PlaygroundSupport

PlaygroundPage.current.setLiveView(ContentView())