Load images from S3 bucket to uiTableView - ios

Question

I have a table view that loads images from s3 bucket and set some data with the images in my cell.
I call my cell at
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cellDish:DishTableViewCell = tableView.dequeueReusableCell(withIdentifier: "DishCell", for: indexPath) as! DishTableViewCell
cellDish.setDish(dish: brain.listOfDishes[indexPath.row])
return cellDish }
in my tableviewcell I have a func called setDish :
func setDish (dish: Dish)
{
var StringPrice = dish.DishPrice
StringPrice.append("$")
self.la_name.text = dish.DishName
self.la_price.text = StringPrice
self.la_des.text = dish.DishDes
self.downloadData(dish: dish, completion: { success in
guard success else { return }
DispatchQueue.main.async {
self.dish_image.image = UIImage(data: dish.DishData!)!
}
})
}
func downloadData(dish:Dish,completion: #escaping (Bool) -> Void) {
let transferUtility = AWSS3TransferUtility.default()
let expression = AWSS3TransferUtilityDownloadExpression()
let s3Bucket = "<my bucket name>"
transferUtility.downloadData(fromBucket: s3Bucket, key: dish.DishImage, expression: expression) {(task, url, data, error) in
if error != nil {print(error)
completion(false)
}
else {
dish.DishData = data!
}
completion(true)
}
}
I want it to show me the dish data without the image until the image is downloaded and then show it to me as well (I want it to be not on the main thread of course ).
I'm not sure why but right now all the cells download their images and only then everything loads up together.

Answer 1

Swift 3 Updated Code :
Load url asynchronous will update automatically
extension UIImageView
{
public func imageFromServerURL(urlString: String)
{
URLSession.shared.dataTask(with: NSURL(string: urlString)! as URL, completionHandler: { (data, response, error) -> Void in
if error != nil {
print(error)
return
}
DispatchQueue.main.async(execute: { () -> Void in
let image = UIImage(data: data!)
self.image = image
})
}).resume()
}}
Swift 2.2 Code :
extension UIImageView {
public func imageFromServerURL(urlString: String) {
NSURLSession.sharedSession().dataTaskWithURL(NSURL(string: urlString)!, completionHandler: { (data, response, error) -> Void in
if error != nil {
print(error)
return
}
dispatch_async(dispatch_get_main_queue(), { () -> Void in
let image = UIImage(data: data!)
self.image = image
})
}).resume()
}}