How to display images that in photo gallery that were just selected? - ios

Question

Goal: The user selects photos from her photo gallery > Tap "Done" > Photos show up.
Problem: The photos don't show up immediately after "Done". They do show up if I open the picker again and tap "Cancel."
This worked fine (photo showed up instantly) when I was using UIImagePickerController, but then I switched to ELCImagePickerController for multiple selection and it no longer works.
Hunches
CollectionView that displays all images is not being reloaded? But I tried calling collectionView.reloadData() after the images are selected (on the completionHandler). This did not work.
If helpful, this is my elcImagePickerController function from my ViewController.swift
func elcImagePickerController(picker: ELCImagePickerController!, didFinishPickingMediaWithInfo info: [AnyObject]!) {
println("inside elcImagePickerController")
self.dismissViewControllerAnimated(true, completion: nil)
if (info.count == 0) {
return
}
var pickedImages = NSMutableArray()
for any in info {
let dict = any as! NSMutableDictionary
let image = dict.objectForKey(UIImagePickerControllerOriginalImage) as! UIImage
pickedImages.addObject(image)
}
let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
dispatch_async(dispatch_get_global_queue(priority, 0), {
PHPhotoLibrary.sharedPhotoLibrary().performChanges(
{
for img in pickedImages{
// Request creating an asset from the image
// create multiple creationRequestForAssetFromImage
let createAssetRequest = PHAssetChangeRequest.creationRequestForAssetFromImage(img as! UIImage) // add to main gallery
// / Request editing the album
let albumChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection, assets: self.photosAsset)
// Get a placeholder for the new asset and add it to the album editing request
let assetPlaceholder = createAssetRequest.placeholderForCreatedAsset
albumChangeRequest.addAssets([assetPlaceholder])
}
}, completionHandler: {(success, error) in
NSLog("Adding Image to Library -> %#", (success ? "Success" : "Error"))
picker.dismissViewControllerAnimated(true, completion: nil)
}
)
})

Answer 1

It took me a while to duplicate your scenario and error, but I managed and I found a solution!
You were on the right path with calling collectionView.reloadData() in the completionHandler, but it needed a bit more work.
1)
In my testing scenario, I've used a PHFetchResult called photosAsset as the main source for the UICollectionView (I'm presuming you have a similar setup).
You have to update this PHFetchResult to reflect the recent changes, in my case I used the following line:
self.photosAsset = PHAsset.fetchAssetsInAssetCollection(self.assetCollection, options: nil)
2)
It's correct that you have to reload the view with collectionView.reloadData(), but the code inside of the completionHandler is not run on the main thread/UI thread. So you have to call it like the following:
dispatch_async(dispatch_get_main_queue(), {self.collectionView?.reloadData()})
Sum up:
In final, your completionHandler should look something similar to this:
completionHandler: {(success, error) in
NSLog("Adding Image to Library -> %#", (success ? "Success" : "Error"))
self.photosAsset = PHAsset.fetchAssetsInAssetCollection(self.assetCollection, options: nil)
dispatch_async(dispatch_get_main_queue(), {self.collectionView?.reloadData()})
picker.dismissViewControllerAnimated(true, completion: nil)
}