How can I speed up performQuery in Swift? - swift

Question

So I am creating this app that uses CloudKit to save and fetch images and text from the Cloud. The problem is that I can only access the results after the whole fetch is done. I would like to be able to fetch each record individually as it is fetched. Here is the code.
func fetchPost() {
spinner.startAnimating()
if imageView.image != nil {
spinner.alpha = 0
}
var imageData = [UIImage]()
var text = [String]()
let predicate = NSPredicate(value: true)
let sort = NSSortDescriptor(key: "creationDate", ascending: false)
let query = CKQuery(recordType: "Post",
predicate: predicate)
query.sortDescriptors = [sort]
publicDB.performQuery(query, inZoneWithID: nil) {
results, error in
if error != nil {
dispatch_async(dispatch_get_main_queue()) {
println("Query failed")
return
}
} else {
println("test")
var number = 0
for record in results {
if let pictureRecord = record as? CKRecord {
let post = Post(record: pictureRecord, database: self.publicDB)
let postImageData = post.imageData
let postText = post.text
self.images.append(UIImage(data: postImageData)!)
self.texts.append(postText)
println("\"\(postText)\" is the text. Fetch successful.")
if number == 0 {
self.imageView.image = self.images[0]
self.nameLabel.text = self.texts[0]
}
++number
} else {
println("Records failed")
}
}
}
self.spinner.stopAnimating()
self.spinner.alpha = 1
}
}
Thanks!

Answer 1

If you use CKQueryOperation you can set a callback (recordFetchedBlock) that will be called for each record as it is fetched from the server.