ALAssetsLibrary delete ALAssetsGroup / ALAsset

Question

I have created "photos album" from my App, using IOS AssetsLibrary.

Reading ALAssetsLibrary,ALAssetsGroup and ALAsset documentations, i have seen methods to "addAsset","addAssetsGroupAlbumWithName".

Is there a way to delete PROGRAMMATICALLY my ALAssetsGroup and ALAsset. (the property 'editable' suppose to be TRUE because i create this data).

Answer 1

You can only delete the ALAsset which is created by your app with document API [ALAsset setImageData:metadata:completionBlock:] (But I have not found any API to delete a ALAssetGroup).

1). Add an image "photo.jpg" to your project 2). Save an image to asset library:

ALAssetsLibrary *lib = [ALAssetsLibrary new];
UIImage *image = [UIImage imageNamed:@"photo.jpg"];
[lib writeImageToSavedPhotosAlbum:image.CGImage metadata:@{} completionBlock:^(NSURL *assetURL, NSError *error) {
    NSLog(@"Write image %@ to asset library. (Error %@)", assetURL, error);
}];

3). Go to default gallery, you will find photo.jpg in your "Saved Photos" album.

4). Delete this image from asset library:

ALAssetsLibrary *lib = [ALAssetsLibrary new];
[lib enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
    [group enumerateAssetsUsingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop) {
        if(asset.isEditable) {
            [asset setImageData:nil metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
                NSLog(@"Asset url %@ should be deleted. (Error %@)", assetURL, error);
            }];
        }
    }];
} failureBlock:^(NSError *error) {

}];

5). Go to default gallery, you will find photo.jpg has already been deleted.

Answer 2

This is not possible using any documented API. Only the photos app can delete Albums. If you want this feature to be added to iOS, I would fill a feature request at https://feedbackassistant.apple.com/.

Answer 3

in ios8 deleting photos might be possible using the Photos Framework

Please check the documentation of Photos Framework

For deleting assets refer to PHAssetChangeRequest

+ (void)deleteAssets:(id<NSFastEnumeration>)assets

where assets is an array of PHAsset objects to be deleted.

For deleting collections refer to PHAssetCollectionChangeRequest

+ (void)deleteAssetCollections:(id<NSFastEnumeration>)assetCollections

https://developer.apple.com/library/prerelease/ios/documentation/Photos/Reference/PHAssetChangeRequest_Class/index.html#//apple_ref/occ/clm/PHAssetChangeRequest/deleteAssets: