Swift Swiftui - Saving Color to UserDefaults and use it from @AppStorage-CodePudding

In my App for MacOS and iOS I use colors created from here: https://uiwjs.github.io/ui-color/ and then f.e. Works fine.

Color(red: 1.47, green: 1.9, blue: 2.3).opacity(1)

However for some colors I want them saved in the userDefaults and read/write by UserDefaults.standard methodes and read/write by @AppStorage.

I did try to use, but this gives me runtime errors.

static let infoListRowReadBGColor = Color(red: 2.55, green: 1.71, blue: 1.07).opacity(1)
static let infoListRowUnReadBGColor = Color(red: 2.55, green: 2.12, blue: 1.38).opacity(1)

var defaults = UserDefaults.standard

defaults.setValue(InAppDefaults.infoListRowReadBGColor, forKey: "infoListRowReadBGColor")
defaults.setValue(InAppDefaults.infoListRowUnReadBGColor, forKey: "infoListRowUnReadBGColor")

What do I need to change to get this working, read and write, using UserDefaults.default and @AppStore? I did try the extension methode from a posting around here, but I guess I do something very wrong, because it doesn't work with @AppStorage.

Using XCode 13 and 14 for dev result for MacOS 12 and iOS 15.

CodePudding user response：

you can try converting color into data and store the data instead.

here's a uikit version extending UIColor you can use it for SwiftUI's Color too

import UIKit

extension UIColor {
    class func color(data: Data) -> UIColor {
        try! NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as! UIColor
    }

    func encode() -> Data {
        try! NSKeyedArchiver.archivedData(withRootObject: self, requiringSecureCoding: false)
    }
}

you can persist the color using the encode function and once you retrieve the data, you can pass it on the class func to get the color

CodePudding user response：

You can't by default store Color() in UserDefaults, but you can use @AppStorage and NSKeyedArchiver to achieve this result. The full example and documentation is provided from this article.

Create an extension:

import Foundation
import SwiftUI
import UIKit

extension Color: RawRepresentable {

    public init?(rawValue: String) {
        
        guard let data = Data(base64Encoded: rawValue) else{
            self = .black
            return
        }
        
        do{
            let color = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? UIColor ?? .black
            self = Color(color)
        }catch{
            self = .black
        }
        
    }

    public var rawValue: String {
        
        do{
            let data = try NSKeyedArchiver.archivedData(withRootObject: UIColor(self), requiringSecureCoding: false) as Data
            return data.base64EncodedString()
            
        }catch{
            
            return ""
            
        }
        
    }

}

And use it as such:

@AppStorage("colorkey") var storedColor: Color = .black
    
    var body: some View {
        
        VStack{
            ColorPicker("Persisted Color Picker", selection: $storedColor, supportsOpacity: true)
            }
}