Best way to serialize optional property which has a custom class - swift

Question

I would to use custom classes with optional types in realm.
In order to serialize and work with a CLLocation instance my idea is this:
class MyClass : Object {
dynamic var _coordinates :NSData?
var coordinates :CLLocation? {
get {
if _coordinates == nil {
return nil
}
// we can cache it too to avoid deserialization every time
let coordinatesObj : CLLocation = NSKeyedUnarchiver.unarchiveObjectWithData(_coordinates!) as! CLLocation
return coordinatesObj
}
set(newCoordinates) {
if newCoordinates == nil {
_coordinates = nil
} else {
_coordinates = NSKeyedArchiver.archivedDataWithRootObject(newCoordinates!)
}
}
}
...
}
Is there a better way?
Should we have some sort of protocol in Realm which allow us to return optional NSData for a specific property?
Another idea is to have a custom method like ignoredProperties which can be used to implement the logic to convert an object to NSData? and viceversa for a set of custom properties.

Answer 1

I don't really think there is a better way than that. If you're looking to serve more complex objects than the ones that Realm supports, you'll always need to implement some additional logic to serialize/deserialize that data.
Personally, I'm a fan of the latter method you suggested: add a new property, mark it as ignored, and then manually implement its accessors to perform the necessary logic on the related Realm-backed property.

Answer 2

At this time there is not another way or workaround to manage my issue.
However I've found another much clearner way to handle this needs.
In fact the main concept is the same but it uses flatMap in order to avoid some boilerplate checks.
Hope it helps.
class MyClass: Object {
dynamic var _coordinates: NSData?
var coordinates: CLLocation? {
get {
return _coordinates.flatMap(NSKeyedUnarchiver.unarchiveObjectWithData) as? CLLocation
}
set {
_coordinates = newValue.flatMap(NSKeyedArchiver.archivedDataWithRootObject)
}
}
}