Swift NSURLSession Download Task not retrieving image assets - html

Question

I am downloading an html page which looks like this from a local Jetty 9 server.
<h1>Hello</h1>
<img src="tiles/tile00.jpg">
<img src="tiles/tile01.jpg">
When I navigate to that page in Chrome, my server receives requests for
/
/tiles/tile00.jpg
/tiles/tile01.jpg
/favicon.ico
and the page displays with the images in Chrome.
However when I navigate to that page using the Swift code below, I only receive a request for
/
and the text renders, but the images only render as [?] icons.
#IBAction func displayWebPage(sender: UIButton) {
let h2Url = NSURL(string: "https://localhost:8443")!
let downloadDelegate = Deleg(view: self)
let ses = NSURLSession(
configuration: NSURLSessionConfiguration.defaultSessionConfiguration(),
delegate: downloadDelegate,
delegateQueue: nil
)
ses.downloadTaskWithURL(myUrl).resume()
}
func completed(location: NSURL) {
print("downloaded")
var htmlString = "NON, MERCÍ"
do {
htmlString = try String.init(
contentsOfURL: location,
encoding: NSUTF8StringEncoding
)
} catch {
print("ERRORED OUT")
fatalError()
}
print("contents: \(htmlString)")
self.webView.loadHTMLString(htmlString, baseURL: nil)
}
class Deleg: NSObject, NSURLSessionDelegate, NSURLSessionDownloadDelegate {
var view: ViewController
init(view: ViewController) {
self.view = view
}
func URLSession(
session: NSURLSession,
downloadTask: NSURLSessionDownloadTask,
didFinishDownloadingToURL location: NSURL
) {
self.view.completed(location)
}
}
Is there a way to convince the NSURLSession to download the assets linked-to in the html page that it downloads?
One solution would be to use let the UIWebView download the linked assets, but then I would not be able to use self-signed certificates.