I am creating a map type application, once the user presses a button a pin is dropped to the map at their current location. I am trying to save map pins to an array so that they remain once the app is closed.
Here is my code so far:
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let location = locations.last
let center = CLLocationCoordinate2D(latitude: location!.coordinate.latitude, longitude: location!.coordinate.longitude)
let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.004, longitudeDelta: 0.004))
self.placesMap?.setRegion(region, animated: true)
self.locationManager.stopUpdatingLocation()
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError)
{
print("Error code: " + error.localizedDescription)
}
// Add button action
@IBAction func addButton(sender: AnyObject) {
let annotation = MKPointAnnotation()
annotation.coordinate = CLLocationCoordinate2D(latitude: self.placesMap.userLocation.coordinate.latitude, longitude: self.placesMap.userLocation.coordinate.longitude)
self.placesMap.addAnnotation(annotation)
self.locationManager.startUpdatingLocation()
}
How can I save the pin information to an array which is reloaded each time the app is opened?
If you want to persist data between application launches, and you are not storing much data, the easy way is to use NSUserDefaults. You can do this by saying something like:
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let location = locations.last
let center = CLLocationCoordinate2D(latitude: location!.coordinate.latitude, longitude: location!.coordinate.longitude)
let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.004, longitudeDelta: 0.004))
self.placesMap?.setRegion(region, animated: true)
self.locationManager.stopUpdatingLocation()
let locationDictionary:[String:Double] = ["latitude":center.latitude,"longitude":center.longitude]
var locationArray = [[String:Double]]()
if NSUserDefaults.standardUserDefaults().objectForKey("locationArray") != nil {
locationArray = NSUserDefaults.standardUserDefaults().objectForKey("locationArray") as! [[String:Double]]
}
locationArray.append(locationDictionary)
NSUserDefaults.standardUserDefaults().setObject(locationArray, forKey: "locationArray")
NSUserDefaults.standardUserDefaults().synchronize()
}
You will then need to read out those locations when the app relaunches. You can do that in viewDidLoad. For example:
override func viewDidLoad(){
super.viewDidLoad()
if NSUserDefaults.standardUserDefaults().objectForKey("locationArray") != nil {
for dictionary in NSUserDefaults.standardUserDefaults().objectForKey("locationArray") as! [[String:Double]]{
let center = CLLocationCoordinate2D(latitude: dictionary["latitude"]!, longitude: dictionary["longitude"]!)
let annotation = MKPointAnnotation()
annotation.coordinate = center
self.placesMap.addAnnotation(annotation)
}
}
}
If you want to remove all of the stored locations you can say something like:
func removeStoredLocations(){
NSUserDefaults.standardUserDefaults().removeObjectForKey("locationArray")
NSUserDefaults.standardUserDefaults().synchronize()
}