PhotoKit: includeAllBurstAssets in PHFetchOptions not working

Question

I am trying to use the includeAllBurstAssets of PHFetchOptions. In my camera roll, there are about 5 burst assets (each with about 10 photos).

To enumerate the assets in the Camera Roll I'm doing the following:

PHFetchOptions *fetchOptions = [PHFetchOptions new];

fetchOptions.includeAllBurstAssets = YES;

PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:fetchOptions];
PHFetchResult *assetFetch = [PHAsset fetchAssetsInAssetCollection:fetchResult[0] options:fetchOptions];

NSLog(@"Found assets %lu",(unsigned long)assetFetch.count);

No matter, if I set the includeAllBurstAssets property to NO or YES, I get the exact same count of assets. I expected the number to be higher, if includeAllBurstAssets is set to YES. Is this a bug or I am interpreting the includeAllBurstAssets in a wrong way.

Answer 1

There is a special method to query for all images of a burst sequence.

[PHAsset fetchAssetsWithBurstIdentifier:options:]

In your case you need to iterate over your assetFetch object and check if the PHAsset represents a burst.

PHAsset defines the property BOOL representsBurst

If that returns YES, fetch all assets for that burst sequence.

Here is a code snippet that might help to understand:

if (asset.representsBurst) {
    PHFetchOptions *fetchOptions = [PHFetchOptions new];
    fetchOptions.includeAllBurstAssets = YES;
    PHFetchResult *burstSequence = [PHAsset fetchAssetsWithBurstIdentifier:asset.burstIdentifier options:fetchOptions];
    PHAsset *preferredAsset = nil;
    for (PHAsset *asset_ in burstSequence) {
        if (PHAssetBurstSelectionTypeUserPick == asset.burstSelectionTypes || PHAssetBurstSelectionTypeAutoPick == asset.burstSelectionTypes) {
            asset = preferredAsset = asset_;
        }
    }
    if (!preferredAsset) {
        asset = burstSequence.firstObject;
    }
} 

As you can see, the burstSelectionTypes are not always set resp. are sometimes PHAssetBurstSelectionTypeNone for all assets of a burst sequence.