Error with Parse: PFObject does not have a member named 'createdAt' - ios

Question

I am stuck on that issue. I've read the Parse documentation (https://parse.com/docs/ios/guide#queries-query-constraints) but it doesn't helps me that much.
The error
When I try to get "createdAt" or "updatedAt" from a PFObject, I got the following error:
['PFObject'] does not have a member named 'createdAt'
The Code
Here is the (shortened) function:
func loadCheckInData() {
var query = PFQuery(className: "CheckIn")
query.orderByDescending("createdAt")
query.selectKeys(["firstName","lastName","updatedAt","createdAt"])
query.findObjectsInBackgroundWithBlock({
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
println(objects)
// Do something
if let object = objects as? [PFObject] {
println("\(object.createdAt)") <---- Error here
self.CheckedPatients = Array(object.generate())
}
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
})
}
Then I retrieve "firstName", "lastName" (and try to retrieve "createdAt") that are in my "CheckIn" Parse's class with the following code
func collectionView(cellView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
// Add parse data
if let value = CheckedPatients[indexPath.row]["lastName"] as? String {
cell.cellLabelTwo.text = value
}
if let value = CheckedPatients[indexPath.row]["firstName"] as? String {
cell.cellLabel.text = value
}
if let value = CheckedPatients[indexPath.row]["createdAt"] as? String {
cell.cellDay.text = value
}
return cell
}
And I call the function
override func viewDidAppear(animated: Bool) {
loadCheckInData()
}
In fact I tried differents method to get that "createdAt" value, and I can't make it works. Does anyone have an idea (and a quick explanation if possible) it could be nice.
Thank you !

Answer 1

It's simply because updatedAt/createdAt is a property on all PFObjects, no need to retrieve it using a key, just treat it as property.

Answer 2

I figured out how to get the property, thanks to #SanitLee answer. I post my code with the solution so that everybody could see it.
Solution
In my function named loadCheckInData() I added for object in objects { to the findObjectsInBackgroundWithBlock method. See below:
func loadCheckInData() {
var query = PFQuery(className: "CheckIn")
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock({
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
// Do something
if let objects = objects as? [PFObject] {
for object in objects { // <--- Added
// data stored in the var named "CheckedPatient"
self.CheckedPatients = Array(objects.generate())
}
}
} else {
// ...
}
})
}
Then to retrieve the createdAt property inside the cellForItemAtIndexPath function, I changed:
if let value = CheckedPatients[indexPath.row]["createdAt"] as? String {
cell.cellDay.text = value
}
into:
var DateVar : PFObject = CheckedPatients[indexPath.row]
var dateFormatter:NSDateFormatter = NSDateFormatter() // Formating
dateFormatter.dateFormat = "EEEE dd MMM HH:mm"
cell.cellDay.text = dateFormatter.stringFromDate(DateVar.createdAt!)
Now it works as I want. If you have any advice, thorough explanations or improvement about the code, feel free to modify and explain it.
Thanks