How do I use UserDefaults with SwiftUI?

Question

struct ContentView: View {
@State var settingsConfiguration: Settings
    struct Settings {
        var passwordLength: Dou         


        

Answer 1

First, create a property wrapper that will allow us to easily make the link between your Settings class and UserDefaults:

import Foundation

@propertyWrapper
struct UserDefault {    
    let key: String
    let defaultValue: Value

    var value: Value {
        get {
            let data = UserDefaults.standard.data(forKey: key)
            let value = data.flatMap { try? JSONDecoder().decode(Value.self, from: $0) }
            return value ?? defaultValue
        }
        set {
            let data = try? JSONEncoder().encode(newValue)
            UserDefaults.standard.set(data, forKey: key)
        }
    }
}

Then, create a data store that holds your settings:

import Combine
import SwiftUI

final class DataStore: BindableObject {
    let didChange = PassthroughSubject()

    @UserDefault(key: "Settings", defaultValue: [])
    var settings: [Settings] {
        didSet {
            didChange.send(self)
        }
    }
}

Now, in your view, access your settings:

import SwiftUI

struct SettingsView : View {
    @EnvironmentObject var dataStore: DataStore

    var body: some View {
        Toggle(isOn: $settings.space) {
            Text("\(settings.space)")
        }
    }
}