Storing a reference to a camera roll image - Swift 4 - ios

Question

I have a really simple request that is apparently beyond me. All I want to do is allow the user to select an image from the camera roll and then store a ‘reference’ to that image in my app. I can then load the image from the camera roll when I need it.
I do not want to copy the image and save it elsewhere because I feel that it would be wasting space on the phone. I realise that the user could delete the image from their camera roll, but in the case of this app it does not matter. I will simply check for nil just before displaying the image. It will not affect the app functionality.
I can present the ImagePickerController and I am happily getting a UIImage by means of:
info[UIImagePickerControllerOriginalImage]
What I would like to do is use:
info[UIImagePickerControllerReferenceURL]
However, this is being removed and is no longer supported. I have therefore lost several hours of my life looking into PHAsset. This seems fine for retrieval, providing I have something to search for. I cannot seem to write a simple app that gets an image via the UIImagePickerController and then allows me to save a reference/URL/uniqueID etc. that I can then use via some other method to get the image back again.
I am more than happy to be laughed at, providing the person laughing shows me how silly I have been…
All help greatly appreciated.

Answer 1

I needed to check the PHPhotoLibrary.authorizationStatus() programatically as the app was silently failing this. Adding the following to AppDelegate.swift resolved the issue (you need to import Photos):
func applicationDidBecomeActive(_ application: UIApplication) {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
photoLibraryAvailabilityCheck()
}
//MARK:- PHOTO LIBRARY ACCESS CHECK
func photoLibraryAvailabilityCheck()
{
if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
{
}
else
{
PHPhotoLibrary.requestAuthorization(requestAuthorizationHandler)
}
}
func requestAuthorizationHandler(status: PHAuthorizationStatus)
{
if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
{
}
else
{
alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
}
}
//MARK:- CAMERA & GALLERY NOT ALLOWING ACCESS - ALERT
func alertToEncourageCameraAccessWhenApplicationStarts()
{
//Camera not available - Alert
let internetUnavailableAlertController = UIAlertController (title: "Camera Unavailable", message: "Please check to see if it is disconnected or in use by another application", preferredStyle: .alert)
let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
DispatchQueue.main.async {
UIApplication.shared.open(url as URL, options: [:], completionHandler: nil) //(url as URL)
}
}
}
let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
internetUnavailableAlertController .addAction(settingsAction)
internetUnavailableAlertController .addAction(cancelAction)
self.window?.rootViewController!.present(internetUnavailableAlertController , animated: true, completion: nil)
}
func alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
{
//Photo Library not available - Alert
let cameraUnavailableAlertController = UIAlertController (title: "Photo Library Unavailable", message: "Please check to see if device settings doesn't allow photo library access", preferredStyle: .alert)
let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
UIApplication.shared.open(url as URL, options: [:], completionHandler: nil)
}
}
let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
cameraUnavailableAlertController .addAction(settingsAction)
cameraUnavailableAlertController .addAction(cancelAction)
self.window?.rootViewController!.present(cameraUnavailableAlertController , animated: true, completion: nil)
}