Using SDWebImage to copy an image as NSData to Pasteboard

Question

I'm using SDWebImage to load images into a UICollectionView. Then when the user clicks on the image I want to copy it to the Pasteboard so they can paste it into other apps.

The code I am currently using in the didSelectItemAtIndexPath method goes back to the web to copy the image. But the image should already be in the user's cache.

How do I use SDWebImage to grab an image for NSData?

That way the app will first check the cache for the image. I keep running into DataType issues when I try to use SDWebImage.

This is my current code. I want to fix the code in the didSelectItemAtIndexPath:

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    let iCell = collectionView.dequeueReusableCellWithReuseIdentifier("ImageCollectionViewCell", forIndexPath: indexPath) as! ImageCollectionViewCell
    let url = NSURL(string: self.imgArray.objectAtIndex(indexPath.row) as! String)

    iCell.imgView.sd_setImageWithURL(url)

    return iCell
}

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    // Change code below to use SDWebImage

    let url = NSURL(string: self.imgArray.objectAtIndex(indexPath.row) as! String)

    let data = NSData(contentsOfURL: url!)

    if data != nil {
        UIPasteboard.generalPasteboard().setData(data!, forPasteboardType: kUTTypePNG as String)
    } else {
        // Do nothing
    }
}

Answer 1

SDWebImage has a cache. You can access it with SDImageCache. There is customization allowed (different namespaces for caches).

let image = SDImageCache.sharedImageCache.imageFromDiskCacheForKey(url!)‌
if image != nil
{
    let data = UIImagePNGRepresentation(image);
}

You have to check if image is not nil because the downloads are asynchrone. So user may trigger collectionView:didSelectItemAtIndexPath: whereas the image hasn't been downloaded yet, and per se not present in the cache.