Realm Swift: Can't get an object from realm

Question

Im getting a JSON file from the api with versions of different api links so that i will know which information to download again if it is outdated.

I have a Version class which looks like this:

class Version : Object {

dynamic var myKey = NSUUID().uuidString
dynamic var banks_v = 0
dynamic var atms_v = 0

override static func primaryKey() -> String? {
    return "myKey"
}

My idea is to take an old version from realm and to download the new version from api and if the versions dont match I should download the JSON file that I need and update my realm. Im doing it like this:

let newVersion = Version()
for item in json {
     newVersion.banks_v = item.1["banks_v"].intValue
     newVersion.atms_v = item.1["atms_v"].intValue
}

// ---- NEED HELP HERE START                 
let oldVersion = self.realm.object(ofType: Version.self, forPrimaryKey: newVersion.myKey)
// NEED HELP HERE END ----

var rewriteVersion = false
if newVersion.banks_v != oldVersion?.banks_v {
     print(newVersion.banks_v) // prints 3 (correct)
     print(oldVersion?.banks_v) // prints nil (???)
     self.getBanks()
     rewriteVersion = true
}
if newVersion.atms_v != oldVersion?.atms_v {
     self.getAtms()
     rewriteVersion = true
}

if rewriteVersion {
     try! self.realm.write {
          self.realm.add(newVersion, update: true)
     }
}

The problem is that I don't know how to properly get the object from realm. I think this part is wrong:

forPrimaryKey: newVersion.myKey

I also tried putting "myKey" there but it is still nil. Any ideas on this?

Thanks in advance!

Answer 1

I fixed it!

In my model class I replaced my id like this:

dynamic var id = 0

and here:

let oldVersion = self.realm.object(ofType: Version.self, forPrimaryKey: 0)