tableview's Datasource array's value is automatically changes to 0 - ios

Question

var noteList:NSMutableArray = NSMutableArray() // declaration of `noteObjects`
query.findObjectsInBackgroundWithBlock { ( objects, error) -> Void in
if (error == nil) {
let temp: NSArray = objects as NSArray!
self.noteList = temp.mutableCopy() as! NSMutableArray
self.tableView.reloadData()
}else {
print(error!.userInfo)
}
}
//populating noteObjects
i have a tableView who's datasource is an Array 'noteObjects' its type is NSMutableArray , so the problem is that every time i open my tableView my 'noteObjects' array's Value is 0 but then it automatically changes to desired value , how can i say this ? i did this in different stages of my tableViewController -
i printed the noteObjects.count in ViewDidload
override func viewDidLoad() {
super.viewDidLoad()
print("\(noteObjects.count) viewDidlaod3") }
output :
0 viewDidlaod3
inside cellForRowAtindexPath i printed this
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
print("\(noteObjects.count) in cellForAtIndexPath")
return cell }
output :
18 in cellForAtIndexPath
and if i move to another View then again open this tableView it keeps giving the sae result , (note object.count = 0 at first)
i want to use that noteObjects.count so that i can confirm that if the tableView's datasource is empty so i can show a message , but when am using this then its always showing that my tableview is empty because at first noteObjects.count is 0
if details provided above is not enough then please let me know i'll fix it

Answer 1

The api call 'findeObjectsInBackground' is asynchronous meaning the closure is executed later in time when result is obtained in a different thread. So getting back to the main thread and reloading the table view when data is ready will solve the problem. You can read more about these type of closures as they are very common in iOS.
query.findObjectsInBackgroundWithBlock { ( objects, error) -> Void in
if (error == nil) {
let temp: NSArray = objects as NSArray!
dispatch_async(dispatch_get_main_queue(), {
self.noteList = temp.mutableCopy() as! NSMutableArray
self.tableView.reloadData()
})
}
else {
print(error!.userInfo)
}
}

Answer 2

use a if statement after the synchronisation method
if noteObjects.count < 1 {
let Alert = UIAlertView(title: "No Data to Display", message: "ther's nothing bro you should pull to refresh", delegate: self, cancelButtonTitle: "OKAY Got IT")
Alert.show()
}

Answer 3

just moved my code from viewDidLoad to viewDidAppear and it worked For me
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.fetchAllObjectsFromLocalDataStore()
print("\(noteObjects.count) view appears")
if noteObjects.count < 1 {
let Alert = UIAlertView(title: "No Data to Display", message: "ther's nothing bro you should pull to refresh", delegate: self, cancelButtonTitle: "OKAY Got IT")
Alert.show()
}
}
now noteObject.count is getting check after updating its Value