iOS 14 How to trigger Local Network dialog and check user answer?

I found a way to trigger the prompt, receive a callback of the user’s selection, and detect if the user has previously allowed or denied the prompt if it already appeared.
To trigger the permission we use a service discovery API. When the user declines or previously declined we receive an error.
It doesn’t indicate if the permission was granted, so we also published a network service that returns success if the permission has been granted.
By combining the 2 into a single component, we can trigger the prompt and get an indication of approval or decline: Until we receive success from the network service or error from the service discovery we assume that the permission is still pending.

import Foundation
import Network

@available(iOS 14.0, *)
public class LocalNetworkAuthorization: NSObject {
    private var browser: NWBrowser?
    private var netService: NetService?
    private var completion: ((Bool) -> Void)?
    
    public func requestAuthorization(completion: @escaping (Bool) -> Void) {
        self.completion = completion
        
        // Create parameters, and allow browsing over peer-to-peer link.
        let parameters = NWParameters()
        parameters.includePeerToPeer = true
        
        // Browse for a custom service type.
        let browser = NWBrowser(for: .bonjour(type: "_bonjour._tcp", domain: nil), using: parameters)
        self.browser = browser
        browser.stateUpdateHandler = { newState in
            switch newState {
            case .failed(let error):
                print(error.localizedDescription)
            case .ready, .cancelled:
                break
            case let .waiting(error):
                print("Local network permission has been denied: \(error)")
                self.reset()
                self.completion?(false)
            default:
                break
            }
        }
        
        self.netService = NetService(domain: "local.", type:"_lnp._tcp.", name: "LocalNetworkPrivacy", port: 1100)
        self.netService?.delegate = self
        
        self.browser?.start(queue: .main)
        self.netService?.publish()
    }
    
    private func reset() {
        self.browser?.cancel()
        self.browser = nil
        self.netService?.stop()
        self.netService = nil
    }
}

@available(iOS 14.0, *)
extension LocalNetworkAuthorization : NetServiceDelegate {
    public func netServiceDidPublish(_ sender: NetService) {
        self.reset()
        print("Local network permission has been granted")
        completion?(true)
    }
}

How to use:

1. Add LocalNetworkAuthorization class to your project
2. Open .plist file and add “_bonjour._tcp”, “_lnp._tcp.”, as a values under “Bonjour services”
3. Call requestAuthorization() to trigger the prompt or get the authorization status if it already been approved/denied