Changing the property of observableObject from another observableObject - ios

Question

There is a problem of the following nature: it is necessary to create an authorization window for the application, the most logical solution I found the following implementation (I had to do this because the mainView has a tabView which behaves incorrectly if it is in a navigationView)
struct ContentView: View {
#EnvironmentObject var vm: AppSettings
var body: some View {
if vm.isLogin {
MainView()
} else {
LoginView()
}
}
AppSettings looks like this:
struct MyApp: App {
#StateObject var appSetting = AppSettings()
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(appSetting)
}
}
}
class AppSettings: ObservableObject {
#Published var isLogin = false
}
By default, the user will be presented with an authorization window that looks like this:
struct LoginView: View {
#StateObject var vm = LoginViewModel()
var body: some View {
NavigationView {
VStack {
TextField("Email", text: $vm.login)
TextField("Password", text: $vm.password)
Button {
vm.auth()
} label: {
Text("SignIn")
}
}
}
}
}
And finally the loginViewModel looks like this:
class LoginViewModel: ObservableObject {
#Published var login = ""
#Published var password = ""
//#Published var appSettings = AppSettings() -- error on the first screenshot
//or
//#EnvironmentObject var appSettings: AppSettings -- error on the second screenshot
func auth() {
UserAPI().Auth(req: LoginRequest(email: login, password: password)) { response, error in
if let err = error {
// Error Processing
} else if let response = response {
Defaults.accessToken = response.tokens.accessToken
Defaults.refreshToken = response.tokens.refreshToken
self.appSettings.isLogin = true
}
}
}
}
1 error - Accessing StateObject's object without being installed on a View. This will create a new instance each time
2 error - No ObservableObject of type AppSettings found. A View.environmentObject(_:) for AppSettings may be missing as an ancestor of this view
I ask for help, I just can not find a way for the interaction of two observableObject. I had to insert all the logic into the action of the button to implement such functionality
In addition to this functionality, it is planned to implement an exit from the account by changing the isLogin variable to false in various cases or use other environment variables to easily implement other functions
The example is deliberately simplified for an easy explanation of the situation

Answer 1

I would think using only LoginViewModel at top level would be the easiest way to solve this. But if you want to keep both, you can synchronise them with an .onChanged modifier.
class LoginViewModel: ObservableObject {
#Published var login = ""
#Published var password = ""
#Published var isLogin = false
func auth() {
UserAPI().Auth(req: LoginRequest(email: login, password: password)) { response, error in
if let err = error {
// Error Processing
} else if let response = response {
Defaults.accessToken = response.tokens.accessToken
Defaults.refreshToken = response.tokens.refreshToken
isLogin = true
}
}
}
}
struct LoginView: View {
#StateObject var vm = LoginViewModel()
// grab the AppSettings from the environment
#EnvironmentObject var appSetting: AppSettings
var body: some View {
NavigationView {
VStack {
TextField("Email", text: $vm.login)
TextField("Password", text: $vm.password)
Button {
vm.auth()
} label: {
Text("SignIn")
}
// synchronise the viewmodels here
.onChange(of: vm.isLogin) { newValue in
appSetting.isLogin = newValue
}
}
}
}
}