Creating a UIImage from a remote LSR file - swift

Question

I'm trying to create a UIImage with one of Apple's new layered image files that's hosted on a remote server.
The sample code below downloads the lsr file correctly (the data var holds a value), but creating a new NSImage with it results in a nil value. Ignore the fact that this code is synchronous and inefficient.
if let url = NSURL(string: "http://path/to/my/layered/image.lsr") {
if let data = NSData(contentsOfURL: url) {
let image = UIImage(data: data) // `image` var is nil here
imageView?.image = image
}
}
Any thoughts on how to download an LSR and create a UIImage with it?

Answer 1

That's how i solved it:
Convert you .lsr file to a .lcr file doing this from console:
xcrun --sdk appletvos layerutil --c your_file.lsr
Upload your_file.lcr on your server
Put these two functions into an util class:
func getDataFromUrl(url:NSURL, completion: ((data: NSData?, response: NSURLResponse?, error: NSError? ) -> Void)) {
NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) in
completion(data: data, response: response, error: error)
}.resume()
}
func downloadImage(url: NSURL, imageView: UIImageView){
print("Started downloading \"\(url.URLByDeletingPathExtension!.lastPathComponent!)\".")
getDataFromUrl(url) { (data, response, error) in
dispatch_async(dispatch_get_main_queue()) { () -> Void in
guard let data = data where error == nil else { return }
print("Finished downloading \"\(url.URLByDeletingPathExtension!.lastPathComponent!)\".")
imageView.image = UIImage(data: data)
}
}
}
Use it like this:
if let checkedUrl = NSURL(string: "http://domain/path/to/your_file.lcr") {
self.my_ui_view.contentMode = .ScaleAspectFit
downloadImage(checkedUrl, imageView: self.my_ui_view.contentMode)
}
This will use the image without saving it into the document directory, if you need that solution, ask me and i'll share.