issue with image cache in getting image back firebase swift iOS - ios

Question

[][!I want load image from download url from firebase using image cache how can I can create an inheritance where my image gets loaded I guess I am missing OOP concept somewhere. my image view is swipe label, how too create an instance where I can display the image on my view.
import UIKit
import Firebase
class swipeLabelViewController: UIViewController {
#IBOutlet weak var UserAgeText: UILabel!
var user:User? {
didSet {
let userNameSwipe = user?.userName
userNameLabel.text = userNameSwipe
let userAgeSwipe = user?.userAge
UserAgeText.text = userAgeSwipe
guard let profileImageUrl = user?.profileImageUrl else {
return }
profileImageView.loadImage(with: profileImageUrl)
print(profileImageUrl)
// let userFetchedImage = user?.profileImageUrl
// swipeLabel.image = userFetchedImage
// self.swipeLabel.image = UIImage(contentsOfFile: profileImageUrl)
}
}
var profileImageView: CustomImageView = {
let iv = CustomImageView()
return iv
}()
var imageI : UIImage!
// var swipepic = CustomImageView()
#IBOutlet weak var swipeLabel: UIImageView!
#IBOutlet weak var userNameLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
swipeLabel.image = imageI
let gesture = UIPanGestureRecognizer(target: self, action:
selector(wasDragged(gestureRecognizer:)))
swipeLabel.addGestureRecognizer(gesture)
fetchCurrentUserData()
}
// user model class``
class User {
// attributes getting users info so i can set up from firebase
var userName:String!
var userAge:String!
var uid:String!
var profileImageUrl: String!
init (uid:String,dictionary:Dictionary) {
self.uid = uid
if let userName = dictionary [ "userName" ] as? String{
self.userName = userName
}
if let userAge = dictionary [ "userAge" ] as? String{
self.userAge = userAge
}
if let profileImageUrl = dictionary["profileImageURL"] as? String {
self.profileImageUrl = profileImageUrl
}
}
}
// and lastly image cache class customImageView
import Foundation
import UIKit
var imageCache = String: UIImage
class CustomImageView: UIImageView {
var lastImgUrlUsedToLoadImage: String?
func loadImage(with urlString: String) {
// set image to nil
self.image = nil
// set lastImgUrlUsedToLoadImage
lastImgUrlUsedToLoadImage = urlString
// check if image exists in cache
if let cachedImage = imageCache[urlString] {
self.image = cachedImage
return
}
// url for image location
guard let url = URL(string: urlString) else { return }
// fetch contents of URL
URLSession.shared.dataTask(with: url) { (data, response, error) in
// handle error
if let error = error {
print("Failed to load image with error",
error.localizedDescription)
}
if self.lastImgUrlUsedToLoadImage != url.absoluteString {
return
}
// image data
guard let imageData = data else { return }
// create image using image data
let photoImage = UIImage(data: imageData)
// set key and value for image cache
imageCache[url.absoluteString] = photoImage
// set image
DispatchQueue.main.async {
self.image = photoImage
}
}.resume()
}
}
no errors I just can't see image on my swipelabel UIImage

Answer 1

You need to make a separate request to download the image from the url that firebase returns. Here is a playground example:
//: A SpriteKit based Playground
import PlaygroundSupport
import UIKit
enum ImageDownloadError: Error {
case failedToConvertDataToImage
}
func dowloadImage(from url: URL, completion: #escaping (Result<UIImage, Error>) -> Void) {
let task = URLSession.shared.dataTask(with: url) { data, response, error in
guard let image = data.flatMap(UIImage.init(data:)) else {
return completion (.failure(error ?? ImageDownloadError.failedToConvertDataToImage))
}
completion(.success(image))
}.resume()
}
let imageView = UIImageView()
dowloadImage(from: URL(string: "https://res.cloudinary.com/demo/image/upload/sample.jpg")!) { [weak imageView] result in
switch result {
case .failure(let error):
print(error.localizedDescription)
case .success(let image):
imageView?.image = image
}
}
imageView.frame = .init(origin: .zero, size: .init(width: 300, height: 300))
PlaygroundPage.current.liveView = imageView
PlaygroundPage.current.needsIndefiniteExecution = true