DidSelectItemAt Collection view issue - ios

Question

I'm having problem with didSelectItemAt in a UICollectionViewCell. I'm using a third party framework to select multiple photos from the library. The selected assets are then transferred and stored in a array of PHAssets. I use a small script for custom preview of the images when tapped on them. (It basically expands the image to full screen and put in and then you can swipe up or down to dismiss it). The problem is not with the images, they're properly displayed in my custom UICollectionViewCell. The problem is when I tap on them. For some reason it gives the wrong image and I'm not sure why.
var cameraPhotoUIImage: UIImage?
var assets = [PHAsset]()
lazy var assetsTurnedIntoImages =
{
return [UIImage]()
}()
lazy var imageManager = {
return PHCachingImageManager()
}()
extension PhotoVC : UICollectionViewDataSource, UICollectionViewDelegate
{
func setupCollectionView()
{
collectionView.dataSource = self
collectionView.delegate = self
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PhotoPostCVCell", for: indexPath) as! PhotoPostCVCell
if let takenImage = cameraPhotoUIImage
{
cell.cellImage.image = takenImage
}
if assets.count > 0
{
let asset = assets[indexPath.row]
imageManager.requestImage(for: asset, targetSize: PHImageManagerMaximumSize, contentMode: .aspectFill, options: nil)
{ (image, info) in
cell.cellImage.contentMode = .scaleAspectFill
cell.cellImage.image = image!
self.assetsTurnedIntoImages.append(image!)
}
}
return cell
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
if assets.count > 0
{
return assets.count
}
else
{
return 1
}
}
// MARK: Preview Selected Image
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let postStoryboard = UIStoryboard(name: Storyboard_Post, bundle:nil)
if let destinationVC = postStoryboard.instantiateViewController(withIdentifier: "PreviewImageVC") as? PreviewImageVC
{
destinationVC.allowedDismissDirection = .both
destinationVC.maskType = .clear
if cameraPhotoUIImage != nil
{
destinationVC.transferedImageToPreview.image = cameraPhotoUIImage
destinationVC.showInteractive()
}
if assetsTurnedIntoImages.count > 0
{
print("Selected image to preview:",assetsTurnedIntoImages[indexPath.row] )
destinationVC.transferedImageToPreview.image = assetsTurnedIntoImages[indexPath.item]
destinationVC.showInteractive()
}
}
}
}

Answer 1

You should update the requestImage method. requestImage method looks like async. So that request does not wait block to complete. If you update your block like this, it should work.
imageManager.requestImage(for: asset, targetSize: PHImageManagerMaximumSize, contentMode: .aspectFill, options: nil)
{ (image, info) in
DispatchQueue.main.async {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PhotoPostCVCell", for: indexPath) as! PhotoPostCVCell
cell.cellImage.contentMode = .scaleAspectFill
cell.cellImage.image = image!
self.assetsTurnedIntoImages.append(image!)
}
}