User Defaults Property Wrappers

UserDefaultsWrappers.swift

import Foundation

@propertyWrapper
struct SimpleUserDefault<T> {
    let userDefaults: UserDefaults
    let key: String
    let defaultValue: T

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

    var wrappedValue: T {
        get {
            guard let data = userDefaults.object(forKey: key) as? T else { return self.defaultValue }
            return data
        }

        set {
            userDefaults.set(newValue, forKey: key)
        }
    }
}

@propertyWrapper
struct OptionalUserDefault<T> {
    let userDefaults: UserDefaults
    let key: String

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

    var wrappedValue: T? {
        get {
            guard let data = userDefaults.object(forKey: key) as? T else { return nil }
            return data
        }

        set {
            if let newValue = newValue {
                userDefaults.set(newValue, forKey: key)
            } else {
                userDefaults.removeObject(forKey: key)
            }
        }
    }
}

@propertyWrapper
struct ComplexUserDefault<T: Codable> {
    let userDefaults: UserDefaults
    let key: String

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

    var wrappedValue: T? {
        get {
            guard let data = userDefaults.data(forKey: key) else { return nil }
            let object = try? JSONDecoder().decode(T.self, from: data)
            return object
        }

        set {
            guard let object = newValue else { return }
            let data = try? JSONEncoder().encode(object)
            userDefaults.set(data, forKey: key)
        }
    }
}

@propertyWrapper
struct ArchiverUserDefault<T: NSObject & NSCoding> {
    let userDefaults: UserDefaults
    let key: String
    let defaultValue: T

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

    var wrappedValue: T {
        get {
            guard let data = userDefaults.data(forKey: key) else { return defaultValue }
            do {
                guard let object = try NSKeyedUnarchiver.unarchivedObject(ofClass: T.self, from: data) else {
                    return defaultValue
                }
                return object
            } catch {
                NonFatalManager.shared.log(
                    "error_unarchiving_user_defaults",
                    "Unable to unarchive data for user defaults (\(key)). Error: \(error)"
                )
                return defaultValue
            }
        }

        nonmutating set {
            do {
                let data = try NSKeyedArchiver.archivedData(withRootObject: newValue, requiringSecureCoding: false)
                userDefaults.set(data, forKey: key)
            } catch {
                NonFatalManager.shared.log(
                    "error_archiving_user_defaults",
                    "Unable to archive data for user defaults (\(key)). Error: \(error)"
                )
                return
            }
        }
    }

    var projectedValue: Binding<T> {
        return Binding(get: {
            return self.wrappedValue
        }, set: {
            self.wrappedValue = $0
        })
    }
}