Asynchronously Downloading The Image From Parse - image

Question

I'm trying to download images from parse via 'Asynchronously'.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath, object: PFObject?) -> PFTableViewCell? {
var cell:CatsTableViewCell? = tableView.dequeueReusableCellWithIdentifier(cellIdentifier) as? CatsTableViewCell
if(cell == nil) {
cell = NSBundle.mainBundle().loadNibNamed("CatsTableViewCell", owner: self, options: nil) [0] as? CatsTableViewCell
}
if let pfObject = object {
cell?.catNameLabel?.text = pfObject["name"] as? String
var votes:Int? = pfObject["votes"] as? Int
if votes == nil {
votes = 0
}
cell?.catVotesLabel?.text = "\(votes!) votes"
var credit:String? = pfObject["cc_by"] as? String
if credit != nil {
cell?.catCreditLabel?.text = "\(credit!) / CC 2.0"
}
cell?.catImageView?.image = nil
if var urlString:String? = pfObject["url"] as? String {
var url:NSURL? = NSURL(string: urlString!)
if var url:NSURL? = NSURL(string: urlString!) {
var error:NSError?
var request:NSURLRequest = NSURLRequest(URL: url!, cachePolicy: NSURLRequestCachePolicy.ReturnCacheDataElseLoad, timeoutInterval: 5.0)
NSOperationQueue.mainQueue().cancelAllOperations()
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {
(response:NSURLResponse?, imageData:NSData?, error:NSError?) -> Void in
cell?.catImageView?.image = UIImage(data: imageData!)
})
}
}
now I changed few code
completionHandler: {
(response:NSURLResponse!, imageData:NSData!, error:NSError!) -> Void in
cell?.catImageView?.image = UIImage(data: imageData)
to
completionHandler: {
(response:NSURLResponse?, imageData:NSData?, error:NSError?) -> Void in
cell?.catImageView?.image = UIImage(data: imageData!)
and no critical errors but the image doesn't show up on the simulator.
Any help would be appreciate. Thank you all.
-first problem-
*And the problem is occurred down below
cell?.catImageView?.image = UIImage(data: imageData)
it says
Value of optional type ‘()?’ not unwrapped; did you mean to use ‘!’ or ‘?’?*

Answer 1

The initializer init(data:) returns an optional UIImage. You should check and unwrap it:
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {
(response: NSURLResponse?, imageData: NSData?, error: NSError?) -> Void in
if let e = error {
print(e)
return
}
guard let data = imageData else { return }
if let image = UIImage(data: data) {
cell?.catImageView?.image = image
}
})