UIImageView.swift

//
//  Created by Mugunth Kumar, Copyright © 2019 MK. All rights reserved.
//

import Foundation
import UIKit
import ImageIO

public extension UIImageView {

  func loadImage(url: URL?) -> URLSessionDataTask? {

    guard let url = url else { return nil }

    let task = URLSession.shared.dataTask(with: url) { [weak self] (imageData, response, error) in
      if let imageData = imageData {
        // perform image decompression so that our scrolling is butter smooth even with plenty of hi-res images
        guard let source = CGImageSourceCreateWithData(imageData as CFData, nil) else { return }
        guard let cgImage = CGImageSourceCreateImageAtIndex(source, 0, // cache the decompressed image
          [(kCGImageSourceShouldCache as String): false] as CFDictionary?) else { return }
        DispatchQueue.main.async {
          guard let superview = self?.superview else { return }
          UIView.transition(with: superview, duration: 0.45, options: [.allowUserInteraction, .transitionCrossDissolve], animations: {
            self?.image = UIImage(cgImage: cgImage, scale: UIScreen.main.scale, orientation: .up)
          }, completion: nil)

        }
      } else {
        if let error = error {
          print ("URL Fetch Failed with error: \(error)")
        }
      }
    }

    task.resume()
    return task
  }
}