Can't change #State var - swift

Question

I have SwiftUI view which I want to change after checking user log-pass. I'm trying to change isAuth var like you can see below.
import SwiftUI
struct Auth : View, AuthProtocol {
#State private var isAuth = false
init() {
userManager.notifier = self
}
var body : some View {
if isAuth {
WelcomeView()
} else {
VStack {
Divider()
Text("Please, wait a minute...")
Divider()
}
.frame(width: 450, height: 350)
}
}
func passAuth() {
if userManager.validateUser() {
self.isAuth.toggle()
print("isAuth: \(isAuth)")
}
}
}
And I got output isAuth: false.
I call passAuth func from this code
class <classname> {
var notifier : AuthProtocol!
func fetchUsers() {
db.collection("users").getDocuments { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for document in querySnapshot!.documents {
var newUser = UserData()
newUser.login = document["login"] as! String
newUser.name = document["name"] as! String
newUser.password = document["password"] as! String
newUser.accessLevel = document["access_level"] as! Int
self.usersList.append(newUser)
}
self.notifier.passAuth()
}
}
}
}
I have no idea why value of isAuth isn't changing...

Answer 1

We use MVVM in swiftui. so we need a viewModel. now when the network request resutl will come we can update our view model and the change will be reflected by the View, simple right? i advice you to check out swiftui tutorials.
struct Auth : View {
#StateObject var viewModel = ViewModel()
// #Binding var isAuth: Bool // should use binding is isAuth will be passed by a parent view
var body : some View {
if viewModel.isAuth {
Text("WelcomeView()")
} else {
VStack {
Divider()
Text("Please, wait a minute...")
Divider()
}
.frame(width: 450, height: 350)
}
}
}
class ViewModel : ObservableObject {
#Published var isAuth = false
func fetchUsers() {
db.collection("users").getDocuments { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for document in querySnapshot!.documents {
var newUser = UserData()
newUser.login = document["login"] as! String
newUser.name = document["name"] as! String
newUser.password = document["password"] as! String
newUser.accessLevel = document["access_level"] as! Int
self.usersList.append(newUser)
}
//
if validateUser() {
self.isAuth = true
}
//
}
}
}
}