Why can I not access the createdAt field of my CKRecord in CloudKit?

Question

I am not able to access the createdAt system field of my record type in CloudKit. I have tried both 'createdAt' and 'creationDate' as the parameter of the CKQueryOperation.desiredKeys argument. Either way, when I access the createdAt field using CKRecord.object(forKey:), I get nil.

Here is my code to retrieve the records:

    entries = [Entry]()

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: DatabaseNameStrings.recordTypeEntry, predicate: predicate)
    let sortDescriptor = NSSortDescriptor(key: DatabaseNameStrings.recordFieldKeyCreationDate, ascending: true)
    query.sortDescriptors = [sortDescriptor]
    let queryOperation = CKQueryOperation(query: query)
    queryOperation.desiredKeys = [DatabaseNameStrings.recordFieldKeyCreationDate, DatabaseNameStrings.fieldNameText]
    queryOperation.recordFetchedBlock = {
        (record: CKRecord) in
        let entry = Entry(ckRecord: record)
        self.entries.append(entry)
    }
    queryOperation.queryCompletionBlock = {
        (cursor: CKQueryOperation.Cursor?, error: Error?) in
        if let error = error {
            print(error.localizedDescription)
        } else {
            DispatchQueue.main.async {
                self.tableView.reloadData()
            }
            if let cursor = cursor {
                let innerQueryOperation = CKQueryOperation(cursor: cursor)
                innerQueryOperation.desiredKeys = queryOperation.desiredKeys
                innerQueryOperation.recordFetchedBlock = queryOperation.recordFetchedBlock
                innerQueryOperation.queryCompletionBlock = queryOperation.queryCompletionBlock
                queryOperationQueue.addOperation(queryOperation)
            }
        }
    }
    queryOperationQueue.addOperation(queryOperation)

Here is the code to the string variables that hold the keys:

enum DatabaseNameStrings {

    static let recordTypeEntry = "Entry"
    static let fieldNameCreatedAt = "createdAt"
    static let fieldNameText = "text"
    static let recordFieldKeyCreationDate = "creationDate"

}

Here is the code where I access the createdAt field:

        print(ckRecord.object(forKey: DatabaseNameStrings.recordFieldKeyCreationDate) as Any)
        print(ckRecord.object(forKey: DatabaseNameStrings.fieldNameCreatedAt) as Any)

Answer 1

I use CKRecord.creationDate instead of CKRecord.object(forKey:).