MacOS: reading shared preferences in Swift and ObjectiveC

Question

I have a project that mixes Swift and objective c. The controller for my preference panes is written in Swift. I can’t seem to read those preferences in Objective C.

This is the code that writes the parameter into the preferences…

let userDefaults = Preferences.shared.getUserDefaults()
@IBAction func DefType(_ sender: NSPopUpButton) {
    var parameter:NSNumber
    parameter = DefType.indexOfSelectedItem + 1 as NSNumber
    userDefaults.set(parameter, forKey: ConstantUtility.StorageKeys.SelectedType.rawValue)
}

func getUserDefaults() -> UserDefaults {
    return UserDefaults.standard
}

The above code is working as the following code is in the function that sets up the preference pane And it initiates the popup correctly.

 func setupUI() {
   var temp1:Int
    temp1 = userDefaults.parameter(forKey: ConstantUtility.StorageKeys.SelectedType.rawValue) ?? 0
    temp1 -= 1
    DefType.selectItem(at: temp1)
}

On the other side of the program is the following code intended to read the preferences. This code always produces an answer of zero.

    - (void) tableViewDoubleTapAction {
        NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
           
        long selectedType = [userDefaults integerForKey:@"SelectedType"];

I'm assuming the problem is in the objectiveC code but I'm open to changing either or both. Been spinning my wheels too long on this one.

Thanks in advance!

Answer 1

I set up a Preferences class as follows...

class Preferences : NSObject {
    private override init() {}
    @objc static let shared = Preferences()
    
    @objc var selectedType: ConstantUtility.SelectedType {
        get {
            let type = UserDefaults.standard.integer(forKey: ConstantUtility.StorageKeys.SelectedType.rawValue)
            guard type != 0, let selectedType = ConstantUtility.SelectedType(rawValue: type) else {
                return ConstantUtility.SelectedType.One
            }
            return type
        }
        set {
            UserDefaults.standard.set(newValue.rawValue, forKey: ConstantUtility.StorageKeys.SelectedType.rawValue)
        }
    }

the swift code to read the preference was changed to

temp1 = userDefaults.integer(forKey: ConstantUtility.StorageKeys.SelectedChart.rawValue)

And the Objective C code became

- (void) tableViewDoubleTapAction {
    long selectedChartType = Preferences.shared.selectedType;

It is all working!