Why is "self" Blocking Data from CloudKit in my QueryOperation - ios

Question

I have multiple CKRecords in my database in Cloudkit. I turn those CKRecords into annotations for my map. Ever since I had to add self before my variable var annotation = MKPointAnnotation() in my queryoperation, it has only been loading one annotation to my Map. Why is that and how do I fix that??? Any help would be amazing!
How I fetch the records -
var points: [MKPointAnnotation] = []
var annotation = MKPointAnnotation()
let database = CKContainer.default().publicCloudDatabase
func fetchTruck() {
let truePredicate = NSPredicate(value: true)
let eventQuery = CKQuery(recordType: "User", predicate: truePredicate)
let queryOperation = CKQueryOperation(query: eventQuery)
queryOperation.recordFetchedBlock = { (record) in
self.points.append(self.annotation)
self.annotation.title = record["username"] as? String
self.annotation.subtitle = record["hours"] as? String
if let location = record["location"] as? CLLocation {
self.annotation.coordinate = location.coordinate
}
print("recordFetchedBlock: \(record)")
self.mapView.addAnnotation(self.annotation)
}
self.database.add(queryOperation)
}

Answer 1

After reviewing in more detail your code I think that the problem is that you are using always the same annotation. MKPointAnnotation is a class, a reference value, that means that every time you assing a value to self.annotation you're changing the reference, not creating a new one.
You're modifiying your app UI (mapView) inside the CKQueryOperation closure. Try to run the modification code in the main thread
Try something like...
var points: [MKPointAnnotation] = []
let database = CKContainer.default().publicCloudDatabase
func fetchTruck()
{
let truePredicate = NSPredicate(value: true)
let eventQuery = CKQuery(recordType: "User", predicate: truePredicate)
let queryOperation = CKQueryOperation(query: eventQuery)
queryOperation.recordFetchedBlock = { (record) in
var annotation = MKPointAnnotation()
annotation.title = record["username"] as? String
annotation.subtitle = record["hours"] as? String
if let location = record["location"] as? CLLocation
{
annotation.coordinate = location.coordinate
}
self.points.append(annotation)
DispatchQueue.main.async
{
self.mapView.addAnnotation(annotation)
}
print("recordFetchedBlock: \(record)")
}
self.database.add(queryOperation)
}