Swift - downcast NSURLResponse to NSHTTPURLResponse in order to get response code

Question

I\'m building rest queries in SWIFT using NSURLRequest

var request : NSURLRequest = NSURLRequest(URL: url)

var connection : NSURLConnection = NSURLConnecti         


        

Answer 1

Use an optional cast (as?) with optional binding (if let):

func connection(didReceiveResponse: NSURLConnection!, didReceiveResponse response: NSURLResponse!) {
    if let httpResponse = response as? NSHTTPURLResponse {
        println(httpResponse.statusCode)
    } else {
        assertionFailure("unexpected response")
    }
}

or as a one-liner

let statusCode = (response as? NSHTTPURLResponse)?.statusCode ?? -1

where the status code would be set to -1 if the response is not an HTTP response (which should not happen for an HTTP request).