How to parse this specific JSON data in Swift 2.0 - json

Question

I'm trying to parse Json Data from an API :
{
"title": "Mr. Robot",
"first_aired": "2015-06-24",
"network": "USA Network",
"channels": [
{
"id": 12,
"name": "USA",
"short_name": "usa",
"channel_type": "television"
}
],
The Code I'm use is:
var TVArray : [TVInfo] = []
var task : NSURLSessionTask?
func getJSON (urlString: String) {
let url = NSURL(string: urlString)!
let session = NSURLSession.sharedSession()
task = session.dataTaskWithURL(url) {(data, response, error) in
dispatch_async(dispatch_get_main_queue()) {
if (error == nil) {
self.updateJSON(data)
}
else {
}
}
}
task!.resume()
}
func updateJSON (data: NSData!) {
let JSONData = (try! NSJSONSerialization.JSONObjectWithData(data, options: []))
TVArray.removeAll(keepCapacity: true)
if let jsonArray = JSONData {
for j in jsonArray {
let title = jsonResult["title"] as! String
let firstAired = jsonResult["first_aired"] as! String
let network = jsonResult["network"] as! String
let channelName = JsonResult["channels"][0]["name"] as! String
let TV = TVInfo(title: title, firstAired: firstAired, network: network, channelName: channelName)
TVArray.append(TV)
}
}
collectionview.reloadData()
}
}
When I use the above code I get an error 'Initializer for conditional binding must have Optional type, not 'AnyObject'' in front of the line 'if let jsonArray = JsonData'. I've tried some methods I've seen on StackOverflow like the method in the link :
[Parsing JSON in swift 2.0
but it didn't work for me. I'm still a bit new to Swift, I really don't want to use SwiftyJSON. Is this the best way to parse this JSON data or is there a better way of doing it?

Answer 1

Since you've used NSJSONSerialization with try! (note the !, meaning it was forced) the value of JSONData is not an optional: you don't have to unwrap it with if let jsonArray = JSONData.
If you still want an optional value, use try? instead.
Otherwise you could also use try inside a do catch block to handle possible errors.

Answer 2

The type of JSONData is unknown, it needs to be known to be an Array for the following for loop.
use:
let JSONData = try! NSJSONSerialization.JSONObjectWithData(data!, options:[]) as! NSArray
You do not need:
if let jsonArray = JSONData {
because you have already crashed if JSONData is nil from the preceding try!
You are better with:
do {
let jsonArray = try NSJSONSerialization.JSONObjectWithData(data!, options:[]) as! NSArray
for j in jsonArray {
// ...
}
} catch {
// handle error
}
Because you have no control over the JSON you receive and crashing because of a server change is not a good idea.
Also really put some time into naming variables, JSONData is not data, it is an array obtained by parsing a JSON string.