How to show and hide loader on Network layer in swiftUI? - ios

Question

I have a Global Singleton network class which handles the response of the API. I want to handle the loader from this class I don't want to manage from each ViewModel individually. I just want to toggle variabe "isLoading" in the ContentView from my global Network class "APIService" But no idea how would I do that?
class APIService {
static let shared = APIService()
private let timeInterval = 60
func makeApiTypeRequest<T: Codable>(
url: String,
param: [String: Any]? = nil,
methodType: HttpMethodType,
expecting: T.Type,
passToken: Bool = true,
completion: #escaping (Result<T, Error>)->Void) {
guard let url = URL(string: url) else {
return
}
var request = URLRequest(url: url, cachePolicy: .reloadIgnoringCacheData, timeoutInterval: TimeInterval(timeInterval))
if let param = param {
let finalData = try? JSONSerialization.data(withJSONObject: param)
request.httpBody = finalData
}
request.httpMethod = methodType.rawValue //"post"
request.addValue("application/json", forHTTPHeaderField: "content-type")
if passToken {
let data = KeychainHelper.standard.read(service: Constant.tokenKey)
if let data = data {
let accessToken = String(data: data, encoding: .utf8)
if let accessToken, accessToken != "" {
let headers = ["Content-Type": "application/json", "Authorization": "Bearer " + accessToken]
request.allHTTPHeaderFields = headers
}
}
}
URLSession.shared.dataTask(with: request) { (data,response,error) in
do {
if let error = error {
completion(.failure(error))
return
}
if let data = data {
if let httpStatus = response as? HTTPURLResponse {
switch httpStatus.statusCode {
case 400:
completion(.failure(CustomError.forbidden))
case 200:
let respObj = try JSONDecoder().decode(T.self, from: data)
completion(.success(respObj))
case 500:
// token expired
DispatchQueue.main.async {
NotificationCenter.default.post(name: Notification.Name("test.token.expired"), object: nil)
}
completion(.failure(CustomError.tokenExpired))
default:
completion(.failure(CustomError.unknown))
}
}
} else {
completion(.failure(CustomError.unknown))
print("no data found")
}
} catch(let error) {
completion(.failure(CustomError.unknown))
print("Error A123 \(error.localizedDescription)")
}
}.resume()
}
}
ContenView
struct ContentView: View {
#EnvironmentObject var session: SessionManager
#State var showMenu: Bool = false
#State var isLoading: Bool = false
#State var isAppInstalled: Bool = false
let pub = NotificationCenter.default
.publisher(for: NSNotification.Name("test.token.expired"))
var body: some View {
return NavigationView {
ZStack {
if isAppInstalled {
if session.currentUserState == .loggedIn {
GeometryReader { geometry in
TabContainer(showMenu: $showMenu)
.frame(width: geometry.size.width, height: geometry.size.height)
if self.showMenu {
MenuView()
.frame(width: geometry.size.width/2)
}
}
} else {
LoginView(showMenu: $showMenu)
}
if isLoading {
Loading()
.ignoresSafeArea()
}
} else {
GettingStartedView(isInstalled: $isAppInstalled)
}
}
.onAppear {
if GettingStartedPersistance.shared.isAppAlreadyInstalled() {
isAppInstalled = true
}
}
.onReceive(pub) { (output) in
self.session.signout()
}
}//.allowsHitTesting(!self.isLoading)
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Sample ViewModel
class LoginViewModel: ObservableObject {
#Published var loginResponse:LoginResponseModel?
#Published var isNavigatedToDashBaord = false
#Published var errorMessage = ""
#Published var isErrorPresented = false
private func validateInputFields(email: String, password: String)->Bool {
if email.isEmpty {
errorOccured(err: "Please enter email")
return false
}
if password.isEmpty {
errorOccured(err: "Please enter password")
return false
}
if !Utils.shared.isValidEmail(strToValidate: email) {
errorOccured(err: "Please enter a valid email")
return false
}
if password.count < 5 {
errorOccured(err: "Password must be atleast 5 characters long")
return false
}
return true
}
func login(email: String, password: String, completion: #escaping (()->())) {
if !validateInputFields(email: email, password: password) {
completion()
return
}
var param = [String: Any]()
param["username"] = email
param["password"] = password
APIService.shared.makeApiTypeRequest(url: APIURLConstant.loginUrl, param: param, methodType: .post, expecting: LoginResponseModel.self, passToken: false) { result in
switch result {
case .success(let loginData):
if loginData.authToken != "" && loginData.authToken != nil {
DispatchQueue.main.async {
self.saveUserToken(token: loginData.authToken ?? "")
self.loginResponse = loginData
self.successlogIn()
completion()
}
} else {
self.errorOccured(err: "Login failled")
completion()
}
case .failure( _):
self.errorOccured(err: "Login failled")
completion()
}
}
}
private func errorOccured(err: String) {
DispatchQueue.main.async {
self.errorMessage = err
self.isErrorPresented = true
}
}
private func successlogIn() {
DispatchQueue.main.async {
self.errorMessage = ""
self.isErrorPresented = false
self.isNavigatedToDashBaord = true
}
}
private func saveUserToken(token: String) {
let accessToken = Data(token.utf8)
KeychainHelper.standard.save(accessToken, service: Constant.tokenKey)
}
}