User info singleton with userdefaults returns nil - ios

Question

I am trying to store user info into userDefaults and assign those to singleton. I am saving the info after successful API call. I know for sure that it saves all those values. But for some reason the singleton returns nil.
This is my User class:
class User {
var id: Int
var name: String
var email: String
var profile_image_url: String
var token: String
init(id: Int, name: String, email: String, profile_image_url: String, token: String) {
self.id = id
self.name = name
self.email = email
self.profile_image_url = profile_image_url
self.token = token
}
init?(dict: [String: JSON]) {
guard let id = dict["id"]?.intValue,
let name = dict["name"]?.stringValue,
let email = dict["email"]?.stringValue,
let profile_image_url = dict["profile_image_url"]?.stringValue,
let token = dict["token"]?.stringValue
else{ return nil }
self.id = id
self.name = name
self.email = email
self.profile_image_url = profile_image_url
self.token = token
}
class var sharedInstance: User {
struct Singleton {
static var instance : User = {
let userDefaults = UserDefaults.standard
let keychain = KeychainSwift()
let user = User(
id: userDefaults.integer(forKey: "user_id"),
name: userDefaults.string(forKey: "name")!,
email: userDefaults.string(forKey: "email")!,
profile_image_url: userDefaults.string(forKey: "profile_image_url")!,
token: keychain.get("token")!
)
return user
}()
}
return Singleton.instance
}
}
And this is how I save values after API call:
class func saveUserData(user_id: Int, name: String, email: String, profile_image_url: String, token:String) {
let userDefaults = UserDefaults.standard
let keychain = KeychainSwift()
keychain.clear()
userDefaults.set(user_id, forKey: "user_id")
userDefaults.set(name, forKey: "name")
userDefaults.set(email, forKey: "email")
userDefaults.set(profile_image_url, forKey: "profile_image_url")
keychain.set(token, forKey: "token")
}
What I am doing wrong, is it even right approach?

Answer 1

As I have mentioned, if you are coding in Swift 4 you should take advantage of the Codable protocol. Make your user a struct that conforms to Codable. You can provide your User struct custom coding keys if needed (not required). Add a method to save your user data to user defaults and create a fallible initializer to read your user data from it:
struct User: Codable {
let id: Int
let name: String
let email: String
let profileImageUrl: String
let token: String
init(id: Int, name: String, email: String, profileImageUrl: String, token: String) {
self.id = id
self.name = name
self.email = email
self.profileImageUrl = profileImageUrl
self.token = token
}
func saveToDefaults() -> Bool {
let encoder = JSONEncoder()
do {
let json = try encoder.encode(self)
UserDefaults.standard.set(json, forKey: "User\(id)Key")
return true
} catch {
print(error)
return false
}
}
init?(data: Data) {
do {
self = try JSONDecoder().decode(User.self, from: data)
} catch {
print(error)
return nil
}
}
init?(id: Int) {
guard let data = UserDefaults.standard.data(forKey: "User\(id)Key") else { return nil }
self.init(data: data)
}
}
Playground testing
let user = User(id: 1, name: "a name", email: "name#email.com", profileImageUrl: "https://i.stack.imgur.com/Xs4RX.jpg", token: "anyTokenString")
if user.saveToDefaults() {
print("success")
if let user = User(id: 1) {
print(user.id)
print(user.name)
print(user.email)
print(user.profileImageUrl)
print(user.token)
} else {
print("there is no user with id 1")
}
}
This will print
success
1
a name
name#email.com
https://i.stack.imgur.com/Xs4RX.jpg
anyTokenString