Navigate after logged in with webservice

Question

I'm making an app in Swift that connects to a web service. I want to make requests, such as login. After logging in, I want to navigate to HomeView but never switch.

I have these files:

` MainView:

struct MainView: View { @ObservedObject var viewModel = MainViewViewModel()

var body: some View {
    if viewModel.savedStudent != nil {
        HomeView()
    } else {
        LoginView()
    }
}

} `

MainViewViewModel:

` class MainViewViewModel: ObservableObject { @Published var savedStudent: Student?

init() {
    loadSavedStudent()
}

func loadSavedStudent() {
    if let savedStudentData = UserDefaults.standard.data(forKey: "student") {
        if let savedStudent = try? JSONDecoder().decode(Student.self, from: savedStudentData) {
            self.savedStudent = savedStudent
        } else {
            print("Error al decodificar el estudiante.")
        }
    } else {
        print("No existe ningun estudiante logueado.")
    }
}

} `

` LoginViewViewModel:

class APIFetchHandler: ObservableObject {
@Published var legajo = ""
@Published var password = ""
@Published var errorMessage = ""

static let sharedInstance = APIFetchHandler()

func postAPIData() {
    
    guard self.validate() else {
        return
    }
    
    let url = "https://webservice.frvm.utn.edu.ar/autogestion/login";
    let headers: HTTPHeaders = [
        "nick": legajo,
        "password": password
    ]
    AF.request(url, method: .post, parameters: nil, encoding: JSONEncoding.default, headers: headers).responseData { response in
        switch response.result {
        case .success(let data):
            do {
                // GUARDA EL ESTUDIANTE EN UserDefaults
                let student = try JSONDecoder().decode(Student.self, from: data)
                if let encodedStudent = try? JSONEncoder().encode(student) {
                    UserDefaults.standard.set(encodedStudent, forKey: "student")
                    UserDefaults.standard.synchronize()
                    print("Student saved to UserDefaults")
                    self.errorMessage = ""
                } else {
                    print("Error encoding student object")
                }
                
                // PRINTEAR UserDefaults PARA VER SI SE GUARDO CORRECTAMENTE
                if let savedStudentData = UserDefaults.standard.data(forKey: "student") {
                    if let savedStudent = try? JSONDecoder().decode(Student.self, from: savedStudentData) {
                        print(savedStudent)
                    } else {
                        print("Error decoding student object")
                    }
                } else {
                    print("No student data found in UserDefaults")
                }
            } catch {
                if let statusCode = response.response?.statusCode, statusCode == 401 {
                    print("Credenciales incorrectas.")
                    self.errorMessage = "Legajo/Contraseña incorrectos."
                }
                return
            }
        case .failure(let error):
            print("------------ ERROR ------------")
            print(error)
            print("------------ ERROR ------------")
        }
    }
}

private func validate() -> Bool {
    guard !legajo.trimmingCharacters(in: .whitespaces).isEmpty,
          !password.trimmingCharacters(in: .whitespaces).isEmpty else {
        self.errorMessage = "Llenar todos los campos, por favor."
        return false
    }

    return true
}

} `

` LoginView:

struct LoginView: View {

@StateObject var viewModel = APIFetchHandler()

var body: some View {
    VStack {
        Text("UTN - FRVM")
            .font(.title)
        
        Text("Iniciar sesión")
        
        Form {
            if !viewModel.errorMessage.isEmpty {
                Text(viewModel.errorMessage)
                    .foregroundStyle(.red)
            }
            
            TextField("Legajo", text: $viewModel.legajo)
                .textFieldStyle(DefaultTextFieldStyle())
            
            SecureField("Password", text: $viewModel.password)
                .textFieldStyle(DefaultTextFieldStyle())
        
            Button {
                viewModel.postAPIData()
            } label: {
                ZStack {
                    RoundedRectangle(cornerRadius: 10)
                    
                    Text("Iniciar sesión")
                        .foregroundColor(.white)
                        .bold()
                }
            }
            .padding()
        }
    }
}

}`