Display result of function in notification title (Swift 3, iOS10)

Question

I'm triggering a local notification from my Swift 3 app in ios10 and, while I can get the notification to fire ok, I'm trying to pass a variable (which happens to be a value returned from a function) as part of the title of the notification. Instead of displaying the contents of that variable it just shows as "(Function)".

I'm using that same variable as the text of a label within the app itself without any problems.

I've created the following class and class function to schedule the notification:

class notificationController {

class func scheduleNotification(at date: Date, header: String, body: String) {

    let calendar = Calendar(identifier: .gregorian)
    let components = calendar.dateComponents(in: .current, from: date)
    let newComponents = DateComponents(calendar: calendar, timeZone: .current, month: components.month, day: components.day, hour: components.hour, minute: components.minute)

    let trigger = UNCalendarNotificationTrigger(dateMatching: newComponents, repeats: false)

    let content = UNMutableNotificationContent()
    content.title = NSString.localizedUserNotificationString(forKey: header, arguments: nil)
    content.body = body
    content.sound = UNNotificationSound.default()

    let request = UNNotificationRequest(identifier: "textNotification", content: content, trigger: trigger)

    UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
    UNUserNotificationCenter.current().add(request) {(error) in
        if let error = error {
            print("error: \(error)")
        }
    }


}

I'm then defining the variables to pass to this function in the viewdidload() function of the view controller associated with the main screen, and then calling the scheduleNotification function:

        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "dd/MM/yyyy HH:mm:ss"
        let strDate = "25/01/2017 21:21:00"
        let notificationDate = dateFormatter.date(from: strDate)
        let dayNumber = String(describing: (playerArray[0]?.calculateDays)!)
        let header = "Welcome to day \(dayNumber) of your life"
        var body : String = ""

    if(infoArray.count > 0) {
        body = (infoArray[0]?.text)!
   } else {body = "Doesn't it feel great to be alive?"}

        notificationController.scheduleNotification(at: notificationDate!, header: header, body: body)

PlayerArray is an array containing one Player CoreData object. I've created the following function within the Player class to work out how many days old the player is:

public class Player: NSManagedObject {

func calculateDays() -> Int {

    let currentCalendar = Calendar.current
    guard let dob = currentCalendar.ordinality(of: .day, in: .era, for: self.dob as! Date) else {
        return 0
    }
    guard let today = currentCalendar.ordinality(of: .day, in: .era, for: Date()) else {
        return 0
    }
    let days = today - dob

    return days
}

}

Any reason that the dayNumber variable won't display? I feel like it's something obvious that I've missed. Any ideas would be magic.

Answer 1

you need to call the function with ()

change this:

    let dayNumber = String(describing: (playerArray[0]?.calculateDays)!)

to this:

    let dayNumber = String(describing: (playerArray[0]?.calculateDays())!)