How to download image with URL Swift 3?

Question

Im a newbie dev and I'm trying to download and display an image from a URL and display it in a UIImage view. I've tried a multiple methods using info from previously asked questions and thr web but it keeps coming up with multiple errors.

Answer 1

There's an excellent example of how to do this in Leo Dabus's answer here. I'll include the relevant bits to your question below.

Using code from that post, I've found one of the easier and cleaner ways is to add an extension to UIImageView:

extension UIImageView {
    func downloadedFrom(url: URL, contentMode mode: UIViewContentMode = .scaleAspectFit) {
        contentMode = mode
        URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let httpURLResponse = response as? HTTPURLResponse, httpURLResponse.statusCode == 200,
                let mimeType = response?.mimeType, mimeType.hasPrefix("image"),
                let data = data, error == nil,
                let image = UIImage(data: data)
                else { return }
            DispatchQueue.main.async() { () -> Void in
                self.image = image
            }
        }.resume()
    }
    func downloadedFrom(link: String, contentMode mode: UIViewContentMode = .scaleAspectFit) {
        guard let url = URL(string: link) else { return }
        downloadedFrom(url: url, contentMode: mode)
    }
}

Then you can just grab the image from your view controller using:

if let url = URL.init(string: urlString) {
    imageView.downloadedFrom(url: url)
}