Where do I specify ReloadIgnoringLocalCacheData for NSURLSession in Swift 2 - ios

Question

I have an app that makes an API call every 5 seconds using NSURLSession and p2-oauth2. I'm running into an issue of it returning cached data instead of the updated information from the API. I read this post by Matt Thompson where he describes the different cache policies, the one I think I need to use is ReloadIgnoringLocalCacheData. I think it's suppose to be put in the AppDelegate DidFinishLaunchingWithOptions functions. But, the problem I'm having is I don't know where or how to specify it. I haven't found any Swift solutions. Can anyone tell me what my function should say?
If it's helpful, here is my API request:
let urlPath = "https://sandbox-api.uber.com/v1/requests/\(uberRequestId)"
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
guard let endpoint = NSURL(string: urlPath) else { print("Error creating endpoint");return }
let request = appDelegate.oauth.request(forURL: NSURL(string:urlPath)!)
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
request.HTTPMethod = "GET"
//get response from Uber and iterate through to find Uber Product ID.
NSURLSession.sharedSession().dataTaskWithRequest(request) { (data, response, error) -> Void in
do {
guard let dat = data else { throw JSONError.NoData }
let result = try NSJSONSerialization.JSONObjectWithData(dat, options: NSJSONReadingOptions.MutableContainers)
print(result)
//set status
status = result["status"] as! String
print("found status...returning it back -> \(status)")
completion(status: "\(status)")
} catch let error as JSONError {
print(error.rawValue)
print("ERROR NEEDS TO BE HANDLED.")
} catch {
print(error)
print("ERROR NEEDS TO BE HANDLED.")
}
}.resume()

Answer 1

Here is the final request that properly sets the cache policy. I added one line with ReloadIgnoringLocalCacheData.
let urlPath = "https://sandbox-api.uber.com/v1/requests/\(uberRequestId)"
let url:NSURL = NSURL(string: urlPath)!
let session = NSURLSession.sharedSession()
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let request = appDelegate.oauth.request(forURL: NSURL(string:urlPath)!)
request.HTTPMethod = "GET"
//added this line to set cache policy
request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = session.dataTaskWithRequest(request) {
(
let data, let response, let error) in
guard let _:NSData = data, let _:NSURLResponse = response where error == nil else {
print("error")
return
}
let dataString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print(dataString)
}
task.resume()

Answer 2

Assuming the OAuth API returns a mutable request, you can set its cachePolicy property to NSURLRequestCachePolicy.ReloadIgnoringCacheData.