Swap elements inside Realm Object

Question

Here's my code in which I want to swap child objects (origin and destination) in Realm:

class TrainSearchOptions: Object {
    dynamic var origin: Station?
    dynamic var destination: Station?
    dynamic var date: Date?

    func swapPlaces() {
        guard origin != nil && destination != nil else {
            fatalError()
        }

        swap(&origin!, &destination!)
    }
}

But this crashes. Any ideas?

Answer 1

You need to do this inside Realm write transaction.

do {
       try realm.write {
           swap(&origin!, &destination!)
       }
   } catch let error as NSError {
       print(error)
   }
}