using a property wrapper for user defaults

UserDefaultWrapper.swift

//
//  UserDefaultStored.swift
//  SwiftUICourse
//
//  Created by Hugo Saynac on 25/06/2020.
//

import Foundation

@propertyWrapper
struct UserDefaultStored<Object: Codable> {

	let key: String
	let encoder = JSONEncoder()
	let decoder = JSONDecoder()
	let userDefaults: UserDefaults

	init(key: String) {
		self.userDefaults = UserDefaults.standard
		self.key = key
	}

	var wrappedValue: Object? {
		get {
			let data = userDefaults.object(forKey: key) as? Data
			return try? data.map { try decoder.decode(Object.self, from: $0) }
		}
		set {
			let encoded = try? encoder.encode(newValue)
			userDefaults.set(encoded, forKey: key)
		}
	}
}


struct MyUser: Codable {
	let name: String
	let nombreDeGlands: Int
}

enum UserInfo {
	@UserDefaultStored(key: "isFirstLaunch") private static var _isFirstLaunch: Bool?
	static var isFirstLaunch: Bool { 
		_isFirstLaunch ?? true 
	}
	@UserDefaultStored(key: "userStore") static var currentUser: MyUser?
}

func exemple() {
	UserInfo.currentUser?.name
}