Realm Async Thread Swift 3 - swift

Question

Using Xcode-8.2.1, Swift-3.0.2, RealmSwift-2.2.0, iOS-Simulator-10:
Trying to write a View-Model with a Realm-Object, I fail at creating a returnArray in another thread. The issue is that the access to the previously created realm-object fails (most likely due to the background-thread access ??).
Can anybody tell me what is wrong with the following code (see below):
Important: It is given that the "createDataEntries()-method" is called before the "getEntries-completionHandler" (as can be seen with correct SimPholders realmobject-entry)! Therefore the "category" is set as "Love" (see code)
import Foundation
import RealmSwift
class MVVMCBalancesModel: BalancesModel
{
fileprivate var entries = [BalancesDataEntry]()
let realm = try! Realm()
init() {
self.createDataEntries()
}
fileprivate func createDataEntries() {
let myBalance = BalancesDataEntry()
myBalance.index = 0
myBalance.category = "Love" // !!!!!!! Here the category is filled
try! self.realm.write {
self.realm.deleteAll()
self.realm.add(myBalance)
}
}
func getEntries(_ completionHandler: #escaping (_ entries: [BalancesDataEntry]) -> Void)
{
// Simulate Aysnchronous data access
DispatchQueue.global().async {
var returnArray: [BalancesDataEntry] = [BalancesDataEntry]()
let realmy = try! Realm()
let cnt = realmy.objects(BalancesDataEntry.self).count
for idx in 0 ..< cnt {
let obj = realmy.objects(BalancesDataEntry.self).filter("index = \(idx)").first!
returnArray.append(obj)
}
completionHandler(returnArray) // !!!!!!! BREAKPOINT (see screenshot below)
}
}
}
Running the above code and setting a breakpoint at the completionHandler(returnArray) produces the following:
Why is the "category" of the returnArray an empty String ???

Answer 1

Properties of objects retrieved from a Realm are lazily retrieved from the underlying storage. Accessing the properties from Swift will return the appropriate values. Likewise, if you run po returnArray from Xcode's LLDB console you should see the object's complete state. The instance variables, shown in the debugger popover, are only used when the object is unmanaged (prior to being added to the Realm).