Best way to use UserDefaults with ObservableObject in Swiftui - swift

Question

I'm trying to save user basic's data in UserDefaults.
My goal is to be able to consume data from UserDefaults and to update them each time the user do some changes.
I'm using an ObservableObject class to set and get these data
class SessionData : ObservableObject {
#Published var loggedInUser: User = User(first_name: "", last_name: "", email: "")
static let shared = SessionData()
func setLoggedInUser (user: User) {
let encoder = JSONEncoder()
if let encoded = try? encoder.encode(user) {
UserDefaults.standard.set(encoded, forKey: "User")
self.loggedInUser = currentUser
}
}
and also
struct ProfileView: View {
#ObservedObject var sessionData: SessionData = SessionData.shared
var body: some View {
VStack{
Text(self.sessionData.loggedInUser.first_name)
}
}
}
This way the changes are updated. But if I leave the app I will lose the data.
Solution 2:
I also tried to rely on reading the data from UserDefault like this
class SessionData : ObservableObject {
func getLoggedInUser() -> User? {
if let currentUser = UserDefaults.standard.object(forKey: "User") as? Data {
let decoder = JSONDecoder()
if let loadedUser = try? decoder.decode(User.self, from: currentUser) {
return loadedUser
}
}
return nil
}
}
Problem: I don't get the updates once a user change something :/
I don't find a nice solution to use both UserDefaults and ObservableObject

Answer 1

in "getLoggedInUser()" you are not updating the published var "loggedInUser".
Try this to do the update whenever you use the function:
func getLoggedInUser() -> User? {
if let currentUser = UserDefaults.standard.object(forKey: "User") as? Data {
let decoder = JSONDecoder()
if let loadedUser = try? decoder.decode(User.self, from: currentUser) {
loggedInUser = loadedUser // <--- here
return loadedUser
}
}
return nil
}
or just simply this:
func getLoggedInUser2() {
if let currentUser = UserDefaults.standard.object(forKey: "User") as? Data {
let decoder = JSONDecoder()
if let loadedUser = try? decoder.decode(User.self, from: currentUser) {
loggedInUser = loadedUser // <--- here
}
}
}
You could also do this to automatically save your User when it changes (instead of using setLoggedInUser):
#Published var loggedInUser: User = User(first_name: "", last_name: "", email: "") {
didSet {
if let encoded = try? JSONEncoder().encode(loggedInUser) {
UserDefaults.standard.set(encoded, forKey: "User")
}
}
}
and use this as init(), so you get back what you saved when you leave the app:
init() {
getLoggedInUser2()
}