Issues with NSURLSession.sharedSession().dataTaskWithURL

Question

I'm trying to load multiple images from the web asynchronously. Looking I found this forum post "Loading/Downloading image from URL on Swift" but I still have some "issues".

I have this code:

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

let newCell = tableView.dequeueReusableCellWithIdentifier("userCell") as! UserCell_TableViewCell
let selectedUser = userArray[indexPath.row]

newCell.userDescription?.text = selectedUser.getFirstName() + " " + selectedUser.getLastName()

if let userImage = selectedUser.getImage()
{
    // NO CODE
}
else
{
    newCell.userImage.downloadedFrom(self.imageArray[arrayIndex])
}

return newCell

}

extension UIImageView {

    func downloadedFrom(urlLink :String)
    {
        if let urlData = NSURL(string: urlLink) {

            NSURLSession.sharedSession().dataTaskWithURL(urlData, completionHandler: { (data, response, error) in

                if error == nil
                {

                    print("Correct URL: " + "\(urlLink)")
                }
                else
                {
                    print("Incorrect URL: " + "\(urlLink)")
                }

            }).resume()
        }
    }
}

PROBLEM

1) to test, I enter right and wrong directions, but always tells me to be correct.

QUESTIONS

1) It is possible that the image can return it for use elsewhere?

2) How do to detect that the URL is invalid and thus enter a default image?

EDIT

Optional( { URL: http://findicons.com/files/icons/1072/face_avatars/300/a03.png } { status code: 200, headers { "Accept-Ranges" = bytes; Connection = "keep-alive"; "Content-Length" = 32759; "Content-Type" = "image/png"; Date = "Fri, 23 Oct 2015 14:20:20 GMT"; "Last-Modified" = "Thu, 11 Feb 2010 10:49:27 GMT"; Server = "nginx/1.1.19"; } })

Optional( { URL: http://findicons.com/files/icons/1072/face_avatars/300/a01_BLABLABLA.png } { status code: 404, headers { Connection = "keep-alive"; "Content-Encoding" = gzip; "Content-Language" = en; "Content-Type" = "text/html; charset=utf-8"; Date = "Fri, 23 Oct 2015 18:01:11 GMT"; Server = "gunicorn/0.17.4"; "Set-Cookie" = "csrftoken=81phPal08h22q6d87lC85TqCCOniJhhJ; expires=Fri, 21-Oct-2016 18:01:11 GMT; Max-Age=31449600; Path=/"; "Transfer-Encoding" = Identity; Vary = "Accept-Encoding, Cookie, Accept-Language"; } })

There you go. You get a 404, there is no such object, your data is empty. What's the problem? — matt
@matt What I need it is if the image exists, put that on my cell UIImageView, if not, leave the default one — avechuche
Sounds good. You do that. I believe I've answered the question. — matt

matt matt · Accepted Answer · 2015-10-23T18:17:24

The response is an NSHTTPURLResponse. If its statusCode is 404 you have no data and should go no further.

The reason you're not getting an error is that there was no error; this is a perfectly valid and complete communication back and forth across the network.

Issues with NSURLSession.sharedSession().dataTaskWithURL

1 Answers