Update whole class in Realm Swift in 1 time wont work - swift

Question

Imagine this code:
class StoredVersions: Object{
#objc dynamic var minimumAppVersion = 0.0
#objc dynamic var sets = 0.0
}
class LoadViewController: UIViewController {
let realm = try! Realm()
override func viewDidLoad() {
super.viewDidLoad()
let db = Firestore.firestore()
var newestVersions = StoredVersions()
if let resultsStoredVersion = self.realm.objects(StoredVersions.self).first{
print("found stored versions: \(resultsStoredVersion)")
self.storedVersions = resultsStoredVersion
}else{
try! self.realm.write {
print("no stored versions")
self.realm.add(self.storedVersions)
}
}
db.collection("data").document("version").getDocument(completion: { (data, someError) in
if let versions = data.flatMap({StoredVersions(value: $0.data()) }) {
try! self.realm.write {
self.storedVersions = versions
}
}
})
}
storedVersions is updated but when I restart the application, storedVersions is back to its initial state. I do see the print "found stored versions".
If I write just 1 variable at a time, it works. That looks like this:
try! self.realm.write {
self.storedVersions.sets = versions.sets
}
How can I update a whole class without having to put in variables one at a time?

Answer 1

When you do this:
if let versions = data.flatMap({StoredVersions(value: $0.data()) }) {
try! self.realm.write {
self.storedVersions = versions
}
}
You're creating a new, unmanaged StoredVersions object. You need to call realm.add(_:) to add it to the Realm, otherwise the object only exists in memory.
If you want to update the existing StoredVersions object rather than creating a new one, you should instead use Realm.add(_:update:), specifying true for the update argument. Note that this requires your type have a primary key property declared so that Realm knows which existing object to update.