So I've made a Button view in my body and I have set it's action to a Google Sign In action, but I want it to also transition to a new view when the sign in flow is completed. The problem is that I have set the label of the button to a Navigation Link and when I click it, it directly transitions to a next view. How can I delay the transition? For context, VoucherView is the next view I want to transition to.

Button {
                    guard let clientID = FirebaseApp.app()?.options.clientID else { return }
                    
                    // Create Google Sign In configuration object.
                    let config = GIDConfiguration(clientID: clientID, serverClientID: GlobalConstants.BACKEND_SERVER_REQUEST_ID_TOKEN)
                    
                    guard let presenter = CommonHelper.GetRootViewController() else {return}
                    
                    // Start the sign in flow!
                    GIDSignIn.sharedInstance.signIn(with: config, presenting: presenter) {user, error in
                        
                        if let error = error {
                            print (error.localizedDescription)
                            return
                        }
                        
                        guard
                            let authentication = user?.authentication,
                            let idToken = authentication.idToken
                        else {
                            print ("Something went wrong!")
                            return
                        }
                        
                        print (authentication)
                        print (idToken)
                        
                        let credential = GoogleAuthProvider.credential(withIDToken: idToken,
                                                                       accessToken: authentication.accessToken)
                        print (credential)
                        UserManager.shared.firebaseAuthentication(credential: credential)
                        signed = true
                        
                    }
                } label: {
                    NavigationLink {
                        
                        VoucherView()
                        
                    } label: {
                        Text("Sign In")
                    }

                }

Edit: After I tried using isValid as a @State variable, after every cycle of SignIn and SignOut the screen goes down.

First SignIn

FirstSignOut

SecondSignIn

SecondSignOut

CodePudding user response：

Instead of using NavigationLink inside your Button, you can use a NavigationLink with an EmptyView for a label and then activate it programmatically with the isActive parameter.

See the following example -- the Google Sign In process is replaced by just a simple async closure for brevity.

struct ContentView: View {
    @State private var navigateToNextView = false
    
    var body: some View {
        NavigationView {
            VStack {
                Button {
                    DispatchQueue.main.asyncAfter(deadline: .now()   1) {
                        navigateToNextView = true
                    }
                } label: {
                    Text("Sign in")
                }
                NavigationLink(destination: View2(), isActive: $navigateToNextView) { EmptyView()
                }
            }
        }.navigationTitle("Test")
    }
}

struct View2 : View {
    var body: some View {
        Text("Next view")
    }
}

A couple more notes:

• Note that there has to be a NavigationView (make sure it's just one) in the hierarchy for this to work
• In general, async work is better done in an ObservableObject than in a View. You can consider moving your login function to an ObservableObject and making the navigateToNextView a @Published property on that object.