Getting the URL of picture taken by camera with Photos Framework - ios

Question

I have an app that uses a UIImagePickerController to retrieve pictures both from camera and from the photos library.
In the image picker delegate I only want to save the NSURL (UIImagePickerControllerReferenceURL) of the picked image to save memory. When the user needs to see the image later on, I load it with PHCachingImageManager directly from the photos library.
Now - this whole thing works great with pictures the user chooses from the library, but not with pictures directly taken by camera (since there is no URL). I am currently trying to save the picture with PHAsset, but I have no idea how to get the NSURL of the save picture.
This is what I've been up to:
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])
{
picker.dismissViewControllerAnimated(true, completion: nil)
let pickedImage = info[UIImagePickerControllerOriginalImage] as! UIImage
if picker.sourceType == .Camera
{
// When taking a picture with the camera, store it in the user roll
PHPhotoLibrary.sharedPhotoLibrary().performChanges(
{ () -> Void in
// save the image
PHAssetCreationRequest.creationRequestForAssetFromImage(pickedImage)
// TODO how to get the asset url
}, completionHandler:
{ (finished, error) -> Void in
if (finished)
{
}
}
)
}
else
{
let pickedImageUrl: NSURL? = info[UIImagePickerControllerReferenceURL] as? NSURL
currentImageUrl = pickedImageUrl
currentImage = pickedImage
toggleImageInfoView(true)
toggleMapState(true)
}
}
Any ideas how to get the url of the saved picture?
Best,
Georg

Answer 1

UPDATE: Seems like I found an answer to this Problem.
Step 1: I save the image to the camera
UIImageWriteToSavedPhotosAlbum(image.image, self, #selector(cameraImageSavedAsynchronously), nil)
this is done asynchronously, so make sure to set a selector when operation has finished.
Step 2: When operation has completed, I do the following:
func fetchLastImage(completion: (localIdentifier: String?) -> Void)
{
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
fetchOptions.fetchLimit = 1
let fetchResult = PHAsset.fetchAssetsWithMediaType(.Image, options: fetchOptions)
if (fetchResult.firstObject != nil)
{
let lastImageAsset: PHAsset = fetchResult.firstObject as! PHAsset
completion(localIdentifier: lastImageAsset.localIdentifier)
}
else
{
completion(localIdentifier: nil)
}
}
I fetch the last image in camera roll with PHAsset and save the local identifier of the image. This is not an URL, but a unique identifier which does not change. This way, you can access the saved image perfectly.
Hope this helps others!

Answer 2

I agree with you.
but, if the Image's Exif has the date of the earlier .
let fetchResult = PHAsset.fetchAssetsWithMediaType(.Image, options: fetchOptions)
fetchResult.firstObject
fetchResult.firstObject is not the one you just saved.
maybe you can modify fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false) to key: "modificationDate"
BTW, I found an other way:
__block PHObjectPlaceholder *placeholderAsset = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetChangeRequest *newAssetRequest = [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:url];
newAssetRequest.location = location;
newAssetRequest.creationDate = [NSDate date];
placeholderAsset = newAssetRequest.placeholderForCreatedAsset;
} completionHandler:^(BOOL success, NSError *error) {
if(success){
PHAsset *asset = [self getAssetFromlocalIdentifier:placeholderAsset.localIdentifier];
completionBlock(asset, YES);
} else {
completionBlock(nil, NO);
}
}];
can get the newly PHAsset.

Answer 3

Ive updated the answer to include returning any asset type, as well as simpler/cleaner way of returning the asset.
Theres no need to a competition handler.
func fetchLastAsset() -> PHAsset? {
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
fetchOptions.fetchLimit = 1
let fetchResult = PHAsset.fetchAssets(with: fetchOptions)
return fetchResult.firstObject
}