Swift 3: Display Image from URL

Question

In Swift 3, I am trying to capture an image from the internet, and have these lines of code:

var catPictureURL = NSURL(fileURLWithPath: \"http://i.imgur.com/         


        

Answer 1

Swift

Good solution to extend native functionality by extensions

import UIKit
    
extension UIImage {
  convenience init?(url: URL?) {
    guard let url = url else { return nil }
            
    do {
      self.init(data: try Data(contentsOf: url))
    } catch {
      print("Cannot load image from url: \(url) with error: \(error)")
      return nil
    }
  }
}

Usage

Convenience initializer is failable and accepts optional URL – approach is safe.

imageView.image = UIImage(url: URL(string: "some_url.png"))

Answer 2

Use extension for UIImageView to Load URL Images.

let imageCache = NSCache<NSString, UIImage>()

extension UIImageView {

    func imageURLLoad(url: URL) {

        DispatchQueue.global().async { [weak self] in
            func setImage(image:UIImage?) {
                DispatchQueue.main.async {
                    self?.image = image
                }
            }
            let urlToString = url.absoluteString as NSString
            if let cachedImage = imageCache.object(forKey: urlToString) {
                setImage(image: cachedImage)
            } else if let data = try? Data(contentsOf: url), let image = UIImage(data: data) {
                DispatchQueue.main.async {
                    imageCache.setObject(image, forKey: urlToString)
                    setImage(image: image)
                }
            }else {
                setImage(image: nil)
            }
        }
    }
}

Answer 3

The easiest way according to me will be using SDWebImage

Add this to your pod file

  pod 'SDWebImage', '~> 4.0'

Run pod install

Now import SDWebImage

      import SDWebImage

Now for setting image from url

    imageView.sd_setImage(with: URL(string: "http://www.domain/path/to/image.jpg"), placeholderImage: UIImage(named: "placeholder.png"))

It will show placeholder image but when image is downloaded it will show the image from url .Your app will never crash

This are the main feature of SDWebImage

Categories for UIImageView, UIButton, MKAnnotationView adding web image and cache management

An asynchronous image downloader

An asynchronous memory + disk image caching with automatic cache expiration handling

A background image decompression

A guarantee that the same URL won't be downloaded several times

A guarantee that bogus URLs won't be retried again and again

A guarantee that main thread will never be blocked Performances!

Use GCD and ARC

To know more https://github.com/rs/SDWebImage