CoreSpotlight Indexing - Image Loading

Question

I am assigning values to CSSearchableItem using CoreSpolight framework. I want to optimise image loading.

func setupSearchableContent(moviesInfo:NSMutableArray)
{
    if #available(iOS 9.0, *)
    {
        var searchableItems = [CSSearchableItem]()

        for i in 0...(moviesInfo.count - 1)
        {

            let searchableItemAttributeSet = CSSearchableItemAttributeSet(itemContentType: kUTTypeText as String)

            // Set the title
            searchableItemAttributeSet.title = (moviesInfo[i] as! ICFAssetObject).title!

            // Movie Image
            if let tempPosterImage = (moviesInfo[i] as! ICFAssetObject).portraitImage()
            {
                searchableItemAttributeSet.thumbnailData = getImageFromURL(tempPosterImage) //imageData
            }

            // Set the Description
            searchableItemAttributeSet.contentDescription = (moviesInfo[i] as! ICFAssetObject).description!

            //Set the Link and Slug
            let values = NSString(format: "%@||%@", (moviesInfo[i] as! ICFAssetObject).link!,(moviesInfo[i] as! ICFAssetObject).slug!)

            let searchableItem = CSSearchableItem(uniqueIdentifier:values as String ,domainIdentifier: "taimur_assets", attributeSet: searchableItemAttributeSet)

            searchableItem.expirationDate = NSDate.distantFuture()
            searchableItems.append(searchableItem)

            CSSearchableIndex.defaultSearchableIndex().indexSearchableItems([searchableItem])
            {
                (error: NSError?) -> Void in

                if let error = error
                {
                    print("Indexing error: \(error.localizedDescription)")
                }
                else
                {
                    print("Search item successfully indexed!")
                }
            }
        }
    }
    else
    {
        // Fallback on earlier versions
    }
}
func getImageFromURL(var fileURL:String) -> NSData
{
     fileURL = NSString(format: "%@/180x180", fileURL) as String
     let data:NSData = NSData(contentsOfURL: NSURL(string: fileURL)!)!
     return data
}

It takes lot of time and application is hanged while the images are downloaded.

thumbnailURL doesn't work. Images are not assigned

When I try to download it in the background. It doesn't assign images to the CSSearchableIndex and Images are not displayed

let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
dispatch_async(dispatch_get_global_queue(priority, 0))
{
      let data:NSData = self.getImageFromURL(movie.Image) //imageData
      dispatch_async(dispatch_get_main_queue())
      {
           searchableItemAttributeSet.thumbnailData = data
      }
}

Answer 1

Here we Go! Issue Fixed

let priority = DISPATCH_QUEUE_PRIORITY_BACKGROUND
dispatch_async(dispatch_get_global_queue(priority, 0))
{
      let data:NSData = self.getImageFromURL(movie.Image) //imageData
      dispatch_async(dispatch_get_main_queue())
      {
           searchableItemAttributeSet.thumbnailData = data
      }
}