I am new to swiftUI. I have one application in which i am making api call, in this application i want to display error if API does not return the response. When i navigate first time to the screen, it displays alert message, but when i go back to previous screen and again navigate back to same screen. alert is not displayed.

struct DashboardView: View {

@ObservedObject var viewModel = DashboardViewModel() @State private var showingAlert = true init() { UINavigationBar.appearance().titleTextAttributes = [.foregroundColor: UIColor.black] self.showingAlert = true } var body: some View { ZStack { Color.white if case .LOADING = viewModel.currentState { loaderView() .onAppear(perform: viewModel.getDashboardData) } else if case .SUCCESS(let dashboard) = viewModel.currentState { ScrollView(.vertical, showsIndicators: false) { VStack(alignment: .leading, spacing: 10) { HStack { Text("Date:") .foregroundColor(Color.black) Text(dashboard.date) .foregroundColor(Color.black) } VStack(alignment: .leading) { Text("HDURL:") .foregroundColor(Color.black) Text(dashboard.hdurl) .foregroundColor(Color.black) } HStack { Text("Media Type:") .foregroundColor(Color.black) Text(dashboard.mediaType) .foregroundColor(Color.black) } HStack { Text("Service Version:") .foregroundColor(Color.black) Text(dashboard.serviceVersion) .foregroundColor(Color.black) } VStack(alignment: .leading) { Text("Title:") .foregroundColor(Color.black) Text(dashboard.title) .foregroundColor(Color.black) } VStack(alignment: .leading) { Text("url:") .foregroundColor(Color.black) Text(dashboard.url) .foregroundColor(Color.black) } VStack(alignment: .leading) { Text("Explanation:") .foregroundColor(Color.black) Text(dashboard.explanation) .foregroundColor(Color.black) } } .padding(.horizontal, 10) .padding(.top, UIApplication.shared.keyWindow!.safeAreaInsets.top ) } .padding(.top, UIApplication.shared.keyWindow!.safeAreaInsets.top ) } else if case .FAILURE(let error) = viewModel.currentState { VStack { Text("No Data") .foregroundColor(Color.black) } } } .navigationBarTitle("Dashboard", displayMode: .inline) .alert(item: $viewModel.appError) { appAlert in Alert(title: Text("Error"), message: Text(""" \(appAlert.errorString) Please try again later! """ ) ) } .ignoresSafeArea(.all) } 

}

enum ViewStateDashboard { case START case LOADING case SUCCESS(dashboardModel: Dashboard) case FAILURE(error: String) }

protocol FetchDashboardDataFromServer { func getDashboardData() var currentState: ViewStateDashboard { get set } }

class DashboardViewModel: ObservableObject, FetchDashboardDataFromServer {

struct AppError: Identifiable { let id = UUID().uuidString let errorString: String } @Published var appError: AppError? let monitor = NWPathMonitor() let monitorPostUser = NWPathMonitor() let queue = DispatchQueue(label: "InternetConnectionMonitor") var cancelable: Set<AnyCancellable> = [] @Published var currentState: ViewStateDashboard = .START init() { self.currentState = .LOADING } // GET Method func getDashboardData() { print("fetch dashboard data") self.currentState = .LOADING monitor.pathUpdateHandler = { pathUpdateHandler in if pathUpdateHandler.status == .satisfied { APIClient.dispatch( APIRouter.GetDashboardData(queryParams: APIParameters.GetDasbhboardParams(apikey: "bWrk8rdLvkzZG5fHgMBQfU9t0xYFdhC6jOT5UKsY"))) .sink { completion in switch completion { case .finished: print("Execution Finihsed dashboard.") case .failure(let error): DispatchQueue.main.async { print("dashboard error", error) self.appError = AppError(errorString: error.localizedDescription) self.currentState = .FAILURE(error: error.localizedDescription) } } } receiveValue: { dashboardData in print("received dashboard data", dashboardData) self.currentState = .SUCCESS(dashboardModel: dashboardData) }.store(in: &self.cancelable) } else { DispatchQueue.main.async { self.currentState = .FAILURE(error: StringConstants.NoInterNet) self.appError = AppError(errorString: StringConstants.NoInterNet) print("no internet get users") } } } monitor.start(queue: queue) } 

}

What could be the issue here? Any help would be appreciated.