Unarchive NSData back to NSColor in swift - macos

Question

I have archived an NSColor to store it in NSUserDefaults:
var data = NSArchiver.archivedDataWithRootObject(NSColor.redColor())
storage.setObject(data, forKey: "color")
storage.synchronize()
But now I need to get the color back from NSData, I have no idea how to do that

Answer 1

You just need to use if let to unwrap your NSData and also you will need a conditional cast as follow:
edit/update:
Swift 3 or later
// archiving
let color: NSColor = .red
let data = NSKeyedArchiver.archivedData(withRootObject: color)
UserDefaults.standard.set(data, forKey: "color")
// unarchiving
if let loadedData = UserDefaults.standard.data(forKey: "color"),
let loadedColor = NSKeyedUnarchiver.unarchiveObject(with: loadedData) as? NSColor {
// you can access loadedColor here
print(loadedColor) // "sRGB IEC61966-2.1 colorspace 1 0 0 1\n"
}

Answer 2

Ran into some errors trying to get Leo's answer working in Swift 5. Came up with this extension which lets UserDefaults store and retrieve colors. Try pasting this into a Playground.
import Cocoa
extension UserDefaults {
func set(_ color: NSColor, forKey: String) {
if let data = try? NSKeyedArchiver.archivedData(withRootObject: color, requiringSecureCoding: false) {
self.set(data, forKey: forKey)
}
}
func color(forKey: String) -> NSColor? {
guard
let storedData = self.data(forKey: forKey),
let unarchivedData = try? NSKeyedUnarchiver.unarchivedObject(ofClass: NSColor.self, from: storedData),
let color = unarchivedData as NSColor?
else {
return nil
}
return color
}
}
// get defaults instance
let defaults = UserDefaults.standard
// create a color
let mycolor = NSColor(red: 0.0, green: 0.5, blue: 0.8, alpha: 0.5)
// save the color
defaults.set(mycolor, forKey: "mycolor")
// read the color back. this returns an optional, may be nil
defaults.color(forKey: "mycolor")