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Editorial Team
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Asked: 2026-06-04T14:37:12+00:00

I seem to be having caching issues with the ALAssetLibrary when testing my app

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I seem to be having caching issues with the ALAssetLibrary when testing my app on the iPhone.

Steps used to produce this issue

  1. Take a photo using the iPhone camera
  2. Access the Camera Roll using ALAssetsLibrary (through ELCImagePicker)

The problem is that when ELCImagePicker displays the list of albums, the thumbnail of the photo taken in step 1 is displayed for the Camera Roll album (which is correct), but when I go into the Camera Roll album, that photo is not there. An error like this is also displayed in the console log:

Cached count is off for 0x2391d0 <x-coredata://D226A7C3-95D5-40B3-BCFB-726E534AB57A/Album/p1> (1357 != 1358) moc=<PLManagedObjectContext: 0x63794c0>

1357 and 1358 appears to be match the photo count before and after I take the photo, and closing the image picker and opening it again doesn’t help. But if I switch to the Photos app, the photo is displayed there. And when I return to my app, the photo is now displayed as well.

I have tried both

UIImageWriteToSavedPhotosAlbum ( UIImage *image, id completionTarget, SEL completionSelector, void *contextInfo );

and ALAssetsLibrary’s

(void)writeImageToSavedPhotosAlbum:(CGImageRef)imageRef orientation:(ALAssetOrientation)orientation completionBlock:(ALAssetsLibraryWriteImageCompletionBlock)completionBlock

but neither works. Any help is greatly appreciated. Thanks!

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1 Answer

  1. Editorial Team

    You can listen for ALAssetsLibraryChangedNotification notification.

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadAlbumGroups) name:ALAssetsLibraryChangedNotification object:nil];

    In reloadAlubmGroups load your album groups from assets library to get updated objects.

    Apple Documentation:

    ALAssetsLibraryChangedNotification

    Sent when the contents of the assets library have changed from under the app that is using the data.
    When you receive this notification, you should discard any cached information and query the assets library again. You should consider invalid any ALAsset, ALAssetsGroup, or ALAssetRepresentation objects you are referencing after finishing processing the notification.

    In iOS v4.0, the notification’s object is nil. In iOS v4.1 and later, the notification object is the library object that posted the notification.

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