Swift: Display image from UIImage array in table view - ios

Question

I am getting images from an async request and adding them to a [UIImage]() so that I can populate my UITableView images with those from the array. The problem is, I keep getting Fatal error: Array index out of range in the cellForRowAtIndexPath function when this is called, and I suspect it may be because I'm making an async call? Why can't I add an image from the array to the table view row?
var recommendedImages = [UIImage]()
var jsonLoaded:Bool = false {
didSet {
if jsonLoaded {
// Reload tableView on main thread
dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.value), 0)) { // 1
dispatch_async(dispatch_get_main_queue()) { // 2
self.tableView.reloadData() // 3
}
}
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
// ...
let imageURL = NSURL(string: "\(thumbnail)")
let imageURLRequest = NSURLRequest(URL: imageURL!)
NSURLConnection.sendAsynchronousRequest(imageURLRequest, queue: NSOperationQueue.mainQueue(), completionHandler: { response, data, error in
if error != nil {
println("There was an error")
} else {
let image = UIImage(data: data)
self.recommendedImages.append(image!)
self.jsonLoaded = true
}
})
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var songCell = tableView.dequeueReusableCellWithIdentifier("songCell", forIndexPath: indexPath) as! RecommendationCell
songCell.recommendationThumbnail.image = recommendedImages[indexPath.row]
return songCell
}
Edit: My numberOfRowsInSection method. recommendedTitles is from the same block of code that I excluded. It's always going to be 6.
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return recommendedTitles.count
}

Answer 1

Your error is you return 6 in numberOfRowsInSection,so tableview know that you have 6 cell
But,when execute cellForRowAtIndexPath,your image array is empty,so it crashed.
Try this
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return recommendedImages.count
}
Also switch to main queue,this is enough
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.tableView.reloadData()
})