How to update EnvironmentObject variable from Coordinator class?

Question

I'm using Coordinator (conforms to LoginButtonDelegate) object to receive user data (profile, name) when user completes authorisation via FB Login Button. Coordinator().userId property is updated with user ID but i need to pass it 1 level up to the LoginView and to update EnvironmentObject called thisSession (make thisSession.userId = Coordinator().userId somehow).

Is there any way to do that? I tried playing with ObservableObject/Published properties but i can't update parent object's properties from Coordinator.

Another idea is to subscribe to Auth.auth() changes but it seems too complicated and a bit "old school" solution. There show be some easy way i am missing.

Any hints/ideas?

import SwiftUI
import FirebaseCore
import FirebaseAuth
import FBSDKLoginKit
import FBSDKCoreKit

struct LoginView: View {
    @EnvironmentObject var thisSession: CurrentSession
    @ObservedObject var mainData = MainViewModel()

    var facebookView = facebook()

    var body: some View {
        VStack {
            facebookView.frame(width: 240, height: 50)
            Text("\(self.thisSession.userId ?? "none")")
        }
    }
}

struct LoginView_Previews: PreviewProvider {
    static var previews: some View {
        LoginView().environmentObject(CurrentSession())
    }
}


struct facebook: UIViewRepresentable {
    @EnvironmentObject var thisSession: CurrentSession
    @ObservedObject var coordinator = Coordinator()

    func makeCoordinator() -> facebook.Coordinator {
        return self.coordinator
        //facebook.Coordinator()
    }

    func makeUIView(context: UIViewRepresentableContext<facebook>) -> FBLoginButton {

        let button = FBLoginButton()
        button.delegate = self.coordinator
        print("UPDATED")

        return button
    }

    func updateUIView(_ uiView: FBLoginButton, context: UIViewRepresentableContext<facebook>) {
    }

    class Coordinator: NSObject, LoginButtonDelegate, ObservableObject {
        @Published var userId: String?
        func loginButton(_ loginButton: FBLoginButton, didCompleteWith result: LoginManagerLoginResult?, error: Error?) {

            if error != nil{

                print((error?.localizedDescription)!)
                return
            }
            if AccessToken.current != nil{

                let credential = FacebookAuthProvider.credential(withAccessToken: AccessToken.current!.tokenString)

                Auth.auth().signIn(with: credential) { (res,er) in

                    if er != nil{
                        print((er?.localizedDescription)!)
                        return

                    }
                    print("email: \(String(describing: res?.user.email))")
                    print("name: \(String(describing: res?.user.displayName))")
                    self.userId = String(describing: res?.user.displayName)
                }
            }
        }

        func loginButtonDidLogOut(_ loginButton: FBLoginButton) {
            print("logged out")
            try! Auth.auth().signOut()

        }
    }

}

Answer 1

Try the following, as coordinator is created during update the environment object should be already injected and present, so it should work

struct facebook: UIViewRepresentable {
    @EnvironmentObject var thisSession: CurrentSession

    func makeCoordinator() -> facebook.Coordinator {
        Coordinator(session: thisSession)              // << here !!
    }

    func makeUIView(context: UIViewRepresentableContext<facebook>) -> FBLoginButton {

        let button = FBLoginButton()
        button.delegate = self.coordinator
        print("UPDATED")

        return button
    }

    func updateUIView(_ uiView: FBLoginButton, context: UIViewRepresentableContext<facebook>) {
    }

    class Coordinator: NSObject, LoginButtonDelegate, ObservableObject {
        let session: CurrentSession
        init(session: CurrentSession) {
            self.session = session
        }

        func loginButton(_ loginButton: FBLoginButton, didCompleteWith result: LoginManagerLoginResult?, error: Error?) {

            if error != nil{

                print((error?.localizedDescription)!)
                return
            }
            if AccessToken.current != nil{

                let credential = FacebookAuthProvider.credential(withAccessToken: AccessToken.current!.tokenString)

                Auth.auth().signIn(with: credential) { (res,er) in

                    if er != nil{
                        print((er?.localizedDescription)!)
                        return

                    }
                    print("email: \(String(describing: res?.user.email))")
                    print("name: \(String(describing: res?.user.displayName))")

                    DispatchQueue.main.async {   // << here 
                        self.session.userId = String(describing: res?.user.displayName)
                    }
                }
            }
        }

        func loginButtonDidLogOut(_ loginButton: FBLoginButton) {
            print("logged out")
            try! Auth.auth().signOut()

        }
    }

}