Wait for result of async function in iOS

Question

I have a question related to my code:

func isNotificationsEnabled()->Bool{
    var isNotificationEnabled = false
    center.getNotificationSettings() { (settings) in
        switch settings.soundSetting{
        case .enabled:
            isNotificationEnabled = true
           break
        case .disabled:
             isNotificationEnabled = false
             break

        case .notSupported:
            isNotificationEnabled = false
             break
        }
    }

     return isNotificationEnabled
}

This function return result before center.getNotificationSettings() returns results. Is there any way to wait for result of center.getNotificationSettings() and sync this function?

Answer 1

What you are looking for is called Completion block in iOS, Try this,

func isNotificationsEnabled(completion:@escaping (Bool)->Swift.Void){
        var isNotificationEnabled = false
        center.getNotificationSettings() { (settings) in
            switch settings.soundSetting{
            case .enabled:
                isNotificationEnabled = true
                completion(isNotificationEnabled)
                break
            case .disabled:
                isNotificationEnabled = false
                completion(isNotificationEnabled)
                break

            case .notSupported:
                isNotificationEnabled = false
                completion(isNotificationEnabled)
                break
            }
        }
    }

Usage,

isNotificationsEnabled { (isNotificationEnabled) in
    debugPrint(isNotificationEnabled)           
}