Limit PHAsset fetch result to only 3 assets

Question

I need to fetch three photos sorted by the date taken - latest being the most recently taken. The way I am currently doing this is by fetching all photo assets then fetching the asset at the appropriate indexes (0, 1, 2). While this works, I am curious if there is a more efficient way to do this when I'm only interested in the top three. The docs explain the fetch doesn't return all image data - only metadata, but I still don't need to obtain all of the metadata. Is there a PHFetchOption I could use to limit the fetch, or an NSPredicate, or is that not necessary to worry about?

var assetsFetchResults = PHAsset.fetchAssetsWithMediaType(.Image, options: nil)
let imageManager = PHCachingImageManager()

if assetsFetchResults?.count > 0 {
    var asset = assetsFetchResults?[0] as? PHAsset
    imageManager.requestImageForAsset(asset, targetSize: targetSize, contentMode: .AspectFill, options: nil, resultHandler: ...)
}
//repeat for index 1 and 2

You can use `fetchKeyAssetsInAssetCollection:options:` to fetch a few KEY photos instead of `fetchAssetsInAssetCollection:options:options:` — k06a, Jun 01 '15 at 23:01
@jarora It worked for me in iOS 8.4.1 in an album created by a third-party app — Jordan H, Sep 07 '15 at 03:13

score 7 · Answer 1 · answered Nov 12 '15 at 18:08

so with iOS 9 you can set PHFetchOptions setting to limit how many you fetch. For example:

   let fetchOptions = PHFetchOptions()
    if #available(iOS 9.0, *) {
        fetchOptions.fetchLimit = 3
    } else {
        // Fallback on earlier versions
    }

However I am also looking for a way to do this on iOS 8 devices as we still have to support both iOS 8 and 9 at this point

Limit PHAsset fetch result to only 3 assets

1 Answers1