SwiftUI authentication view - swift

Question

In swift UI I want the content view to be my root view for my app with a conditional setup to check if the users is logged in or not. If the user is logged in a list view shows other wise show the login view so the user can log in. Based on my research i could not find a best way to do this.
In my case I can not get the solution I found to work and do not know if it is the best solution.
import SwiftUI
struct ContentView: View {
#ObservedObject var userAuth: UserAuth = UserAuth()
// MARK: - View
#ViewBuilder
var body: some View {
if !userAuth.isLoggedin {
return LoginView().environmentObject(userAuth)
}
return BookList()
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
import Combine
class UserAuth: ObservableObject {
let didChange = PassthroughSubject<UserAuth,Never>()
// required to conform to protocol 'ObservableObject'
let willChange = PassthroughSubject<UserAuth,Never>()
func login() {
// login request... on success:
self.isLoggedin = true
}
func logout() {
// login request... on success:
self.isLoggedin = false
}
var isLoggedin = false {
didSet {
didChange.send(self)
}
// willSet {
// willChange.send(self)
// }
}
}
When running this all i get is a white screen. It seems that the view builder might be the problem but removing that i get a opaque error on content view

Answer 1

There two problems with provided code snapshot: 1) incorrect view builder content, and 2) incorrect model.
See below both fixed. Tested with Xcode 11.4 / iOS 13.4
struct ContentView: View {
#ObservedObject var userAuth: UserAuth = UserAuth()
// MARK: - View
#ViewBuilder // no need return inside
var body: some View {
if !userAuth.isLoggedin {
LoginView().environmentObject(userAuth)
}
else {
BookList()
}
}
}
import Combine
class UserAuth: ObservableObject {
#Published var isLoggedin = false // published property to update view
func login() {
// login request... on success:
self.isLoggedin = true
}
func logout() {
// login request... on success:
self.isLoggedin = false
}
}

Answer 2

how about just this:
var body: some View {
if !userAuth.isLoggedin {
LoginView().environmentObject(userAuth)
} else {
BookList()
}
}