Swift NSURL giving error on valid urls - ios

Question

Look at this code:
let url = NSURL(string: physicst.image as String)
if let url = url {
let request = NSMutableURLRequest(URL: url)
let task = session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
if let data = data {
cell.imageView?.image = UIImage(data: data)
}
})
task.resume()
}else {
print ("nill URL \(physicst.image)")
}
so I have a string, and that string is a url, and I want to load it.
that code is in a table view cells, so it is being called for each cell.
as you see, i am checking if the url is nil or not, and if not, i am making a print statement. almost all the urls are not nil, exception the following ones (which are complemetly valid)
http://commons.wikimedia.org/wiki/Special:FilePath/Kai_Manne_Börje_Siegbahn.jpg?width=300
http://commons.wikimedia.org/wiki/Special:FilePath/Виталий_Лазаревич_Гинзбург.jpg?width=300
http://commons.wikimedia.org/wiki/Special:FilePath/赤崎記念研究館.jpg?width=300
http://commons.wikimedia.org/wiki/Special:FilePath/Kai_Manne_Börje_Siegbahn.jpg?width=300
http://commons.wikimedia.org/wiki/Special:FilePath/赤崎記念研究館.jpg?width=300
The first thing you may argue is to encode the url, and that is what I did like this:
var image = oneBinding["p"]!!["value"] as! NSString
image = image.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())!
but then even the urls that were working, stopped working. what i am missing please ?
Update
Here is the whole code of my UITableViewController (it is easy)
class PhysicistTableViewController: UITableViewController {
var physicsts : [Physicst]?
#IBOutlet var physicstsTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
loadDataFromDBPedia()
}
func loadDataFromDBPedia() {
let session = NSURLSession.sharedSession()
var url = "http://dbpedia.org/sparql/"
let query = "http://dbpedia.org&query=select * {?o dbo:thumbnail ?p . ?o dbo:award dbr:Nobel_Prize_in_Physics}"
url = url + "?default-graph-uri=" + query.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())!
url = url + "&format=JSON&CXML_redir_for_subjs=121&CXML_redir_for_hrefs=&timeout=30000&debug=on"
let request = NSMutableURLRequest(URL: NSURL(string: url)!)
let task = session.dataTaskWithRequest(request, completionHandler: {(data, response ,error) in
if let error = error {
print ("\(error)")
}
if let response = response {
let httpResponse = response as! NSHTTPURLResponse
let statusCode = httpResponse.statusCode
print("Status code = \(statusCode)")
}
if let data = data {
do {
let jsonResponse = try NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions())
let binding = jsonResponse["results"]!!["bindings"] as! NSArray
for oneBinding in binding {
let name = oneBinding["o"]!!["value"] as! NSString
let image = oneBinding["p"]!!["value"] as! NSString
//image = image.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())!
let physicst = Physicst(image: image, name: name)
if self.physicsts == nil {
self.physicsts = [Physicst]()
}
self.physicsts!.append(physicst)
}
self.physicstsTableView.reloadData()
}catch _ {
print ("not well json-formatted response")
}
}
})
task.resume()
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if self.physicsts == nil {
return 0
}else {
return self.physicsts!.count
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("physicstCell")! as UITableViewCell
let row = indexPath.row
let physicst = self.physicsts![row]
cell.textLabel?.text = physicst.name as String
if (physicst.imageData == nil) {
let session = NSURLSession.sharedSession()
let url = NSURL(string: physicst.image as String)
if let url = url {
let request = NSMutableURLRequest(URL: url)
let task = session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
if let data = data {
let imageData = UIImage(data: data)
cell.imageView?.image = imageData
physicst.imageData = imageData
self.physicstsTableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.None)
}
})
task.resume()
}else {
print ("nill URL \(physicst.image)")
}
}else {
cell.imageView?.image = physicst.imageData!
}
return cell
}
}

Answer 1

URLHostAllowedCharacterSet only contains this "#%/<>?#\^{|}
And your URL string contains : .. So make custom set for this
let yourString = "http://commons.wikimedia.org/wiki/Special:FilePath/Kai_Manne_Börje_Siegbahn.jpg?width=300"
let customSet = NSCharacterSet(charactersInString:"=\"#%/:<>?#\\^`{|}").invertedSet
let finalString = yourString.stringByAddingPercentEncodingWithAllowedCharacters(customSet)
For more info. check this answer

Answer 2

The method you should use is
stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())
Taken from the playground:
NSURL(string:"http://commons.wikimedia.org/wiki/Special:FilePath/Kai_Manne_Börje_Siegbahn.jpg?width=300".stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!)
Gives the result
http://commons.wikimedia.org/wiki/Special:FilePath/Kai_Manne_B%C3%B6rje_Siegbahn.jpg?width=300
Which is valid :)
Adapted to your code it gives:
let url = NSURL(string: (physicst.image as String).stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet()!)
Beware of the forced unwrapping tho !