Loading image from gallery by local URL (Swift) - ios

Question

I’ve encountered a strange behavior:
An imagePicker returns a PHAsset, and I do the Following and manage to present an imageView with image from the data:
asset.requestContentEditingInput(with: PHContentEditingInputRequestOptions()) { (input, _) in
let url = input?.fullSizeImageURL
let imgV = UIImageView()
let test_url = URL(string: (url?.absoluteString)!)
print("><><><^^^><><>\(test_url)")
//prints: ><><><^^^><><>Optional(file:///var/mobile/Media/DCIM/107APPLE/IMG_7242.JPG)
let data = NSData(contentsOf: test_url! as URL)
imgV.image = UIImage(data: data! as Data)
imgV.backgroundColor = UIColor.cyan
att.imageLocalURL = url?.absoluteString//// saving the string to use in the other class
imgV.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
self.view.addSubview(imgV) /// just to test that the file exists and can produce an image
However when I do the following in another class:
if((NSURL( string: self.attachment.imageLocalURL! ) as URL!).isFileURL)// checking if is Local URL
{
let test_url = URL(string: self.attachment.imageLocalURL!) // reading the value stored from before
print("><><><^^^><><>\(test_url)")
//prints :><><><^^^><><>Optional(file:///var/mobile/Media/DCIM/107APPLE/IMG_7242.JPG)
let data = NSData(contentsOf: test_url! as URL)
imageView.image = UIImage(data: data! as Data)
}
The data is nil! What am I doing wrong, the String for URL is identical in both cases!

Answer 1

PHAsset objects should be accessed via the PHImageManager class. If you want to load the image synchronously I recommend you do something like this:
func getImage(assetUrl: URL) -> UIImage? {
let asset = PHAsset.fetchAssets(withALAssetURLs: [assetUrl], options: nil)
guard let result = asset.firstObject else {
return nil
}
var assetImage: UIImage?
let options = PHImageRequestOptions()
options.isSynchronous = true
PHImageManager.default().requestImage(for: result, targetSize: UIScreen.main.bounds.size, contentMode: PHImageContentMode.aspectFill, options: options) { image, info in
assetImage = image
}
return assetImage
}
You could even write a UIImageView extension to load the image directly from a PHAsset url.

Answer 2

var images:NSMutableArray = NSMutableArray() //hold the fetched images
func fetchPhotos ()
{
images = NSMutableArray()
//totalImageCountNeeded = 3
self.fetchPhotoAtIndexFromEnd(0)
}
func fetchPhotoAtIndexFromEnd(index:Int)
{
let status : PHAuthorizationStatus = PHPhotoLibrary.authorizationStatus()
if status == PHAuthorizationStatus.Authorized
{
let imgManager = PHImageManager.defaultManager()
let requestOptions = PHImageRequestOptions()
requestOptions.synchronous = true
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key:"creationDate", ascending: true)]
if let fetchResult: PHFetchResult = PHAsset.fetchAssetsWithMediaType(PHAssetMediaType.Image, options: fetchOptions)
{
if fetchResult.count > 0
{
imgManager.requestImageForAsset(fetchResult.objectAtIndex(fetchResult.count - 1 - index) as! PHAsset, targetSize: CGSizeMake(self.img_CollectionL.frame.size.height/3, self.img_CollectionL.frame.size.width/3), contentMode: PHImageContentMode.AspectFill, options: requestOptions, resultHandler: { (image, _) in
//self.images.addObject(image!)
if image != nil
{
self.images.addObject(image!)
}
if index + 1 < fetchResult.count && self.images.count < 20 //self.totalImageCountNeeded
{
self.fetchPhotoAtIndexFromEnd(index + 1)
}
else
{
}
})
self.img_CollectionL.reloadData()
}
}
}
}