Why is the function(s) not retrieving the data? - ios

Question

I am trying the get the preview link from the itunes search api. I have a function that will get the information when the button is clicked, but the function is not being called. I want to get the preview link of the first object in the results array How do I fix this?
var d: NSMutableData = NSMutable Data()
var tData: NSArray = NSArray()
func ctn(receivedResponse: NSURLConnection!, receivedResponse response: NSURLResponse!) {
// clear out the data object if a new request was received.
self.d = NSMutableData()
}
func ctn(ctn: NSURLConnection!, receivedData d: NSData!) {
self.d.appendData(d)
}
func ctnFinishedLoading(ctn: NSURLConnection!) throws {
var err: NSError
var jResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(d, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
if jResult.count>0 && jResult["results"]!.count>0 {
var results: NSArray = jResult["results"]as! NSArray
self.tData = results
print(tData)
//self.appsTableView.reloadData()
}
}
func playit(sender: UIButton!) {
let cell = table.dequeueReusableCellWithIdentifier("cell")
let playButtonrow = sender.tag
print(ret[playButtonrow])
let searchTerm: String = ret[playButtonrow]
let itunesSearchTerm = searchTerm.stringByReplacingOccurrencesOfString(" ", withString: "+", options: NSStringCompareOptions.CaseInsensitiveSearch, range: nil)
if let escapedSearchTerm = itunesSearchTerm.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding) {
let urlPath = "https://itunes.apple.com/search?term=\(escapedSearchTerm)&media=music"
let url: NSURL = NSURL(string: urlPath)!
let request: NSURLRequest = NSURLRequest(URL: url)
let ctn: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)!
print("Search iTunes API at URL \(url)")
ctn.start()
}

Answer 1

The way to grab the previewUrl is to grab the value for a single result array member such as the first one having index 0 and then pulling the value for the previewUrl key. For example:
if jResult.count>0 && jResult["results"]!.count>0 {
var results: NSArray = jResult["results"]as! NSArray
if let previewUrl = results[0]["previewUrl"] {
print(previewUrl!)
}
}
Since NSURLConnection is deprecated in iOS 9, I'll also give you a way of using NSURLSession to retrieve the previewUrls from the iTunes API.
let urlPath = "https://itunes.apple.com/search?term=\(escapedSearchTerm)&media=music"
let url: NSURL = NSURL(string: urlPath)!
let task = NSURLSession.sharedSession().dataTaskWithURL(url) {(data, response, error) -> Void in
do {
if let dict: NSDictionary = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary
{
// The search is complete.
for result in dict["results"] as! NSArray {
if let previewUrl = result["previewUrl"] {
print(previewUrl!)
}
}
}
} catch let jsonError as NSError {
// Handle error.
}
}
task.resume()