How to convert PHAsset to UIImage in Objective-C

Question

I have an array filled with PHAsset objects (https://developer.apple.com/library/prerelease/ios/documentation/Photos/Reference/PHAsset_Class/index.html), and I want

Answer 1

Swift 4.2

extension PHAsset {

    var image : UIImage {
        var thumbnail = UIImage()
        let imageManager = PHCachingImageManager()
        imageManager.requestImage(for: self, targetSize: CGSize(width: 100, height: 100), contentMode: .aspectFit, options: nil, resultHandler: { image, _ in
            thumbnail = image!
        })
        return thumbnail
    }
}                          

let image = asset.image