avatarImageDownload networkManager refactor

GHFollowers/Components/Cells/FavoriteCell.swift

@@ -30,7 +30,12 @@ class FavoriteCell: UITableViewCell {
     // setter for the favorite data
     func set(favorite: Follower) {
         usernameLabel.text = favorite.login
-        avatarImageView.downloadImage(from: favorite.avatarUrl)
+        NetworkManager.shared.downloadImage(from: favorite.avatarUrl) { [weak self](image) in
+            guard let self = self else { return }
+            DispatchQueue.main.async {
+                self.avatarImageView.image = image
+            }
+        }
     }
 
 

GHFollowers/Components/Cells/FollowerCell.swift

@@ -34,7 +34,12 @@ class FollowerCell: UICollectionViewCell {
     // on the FollowerListVC View Controller
     func set(follower: Follower) {
         usernameLabel.text = follower.login
-        avatarImageView.downloadImage(from: follower.avatarUrl)
+        NetworkManager.shared.downloadImage(from: follower.avatarUrl) { [weak self](image) in
+            guard let self = self else { return }
+            DispatchQueue.main.async {
+                self.avatarImageView.image = image
+            }
+        }
     }
 
 

GHFollowers/Components/ImageViews/GFAvatarImageView.swift

@@ -30,48 +30,4 @@ class GFAvatarImageView: UIImageView {
         image = placeholderImage
         translatesAutoresizingMaskIntoConstraints = false
     }
-
-    func downloadImage(from urlString: String) {
-
-        // convert urlString to NSString
-        let cacheKey = NSString(string: urlString)
-
-        // cacheKey already cached then return and dont download
-        if let image = cache.object(forKey: cacheKey) {
-            self.image = image
-            return
-        }
-
-        // else go down here and download the image
-
-        // if param is not valid url return
-        guard let url = URL(string: urlString) else { return }
-
-        // make api call
-        let task = URLSession.shared.dataTask(with: url) { [weak self] data, response, error in
-
-            guard let self = self else { return }
-
-            // if calls returns error return
-            if error != nil { return }
-            //if response exists and is not nil and if status code is 200(OK)
-            guard let response = response as? HTTPURLResponse, response.statusCode == 200 else { return }
-            // check if we actually have data returned
-            guard let data = data else { return }
-
-            // pass the server data to the image
-            guard let image = UIImage(data: data) else { return }
-
-            // save downloaded image to chache
-            self.cache.setObject(image, forKey: cacheKey)
-
-            // get on the main thread to update UI
-            DispatchQueue.main.async {
-                self.image = image
-            }
-
-        }
-
-        task.resume()
-    }
 }

GHFollowers/Components/ViewControllers/GFUserInfoheaderVC.swift

@@ -40,7 +40,7 @@ class GFUserInfoheaderVC: UIViewController {
 
 
     func configureUIElements() {
-        avatarImageView.downloadImage(from: user.avatarUrl)
+        downloadAvatarImage()
         usernameLabel.text = user.login
         nameLabel.text = user.name ?? "" // nil coalescing (if null then use placeholder in string)
         locationLabel.text = user.location ?? "No Location"
@@ -53,6 +53,16 @@ class GFUserInfoheaderVC: UIViewController {
     }
 
 
+    func downloadAvatarImage() {
+        NetworkManager.shared.downloadImage(from: user.avatarUrl) { [weak self](image) in
+            guard let self = self else { return }
+            DispatchQueue.main.async {
+                self.avatarImageView.image = image
+            }
+        }
+    }
+
+
 
     // MARK: VIEW FUNCTIONS
 

GHFollowers/Managers/NetworkManager.swift

@@ -21,12 +21,14 @@ class NetworkManager {
 
     // MARK: @escaping closure explenation
     /*
-        Closures can be escaping or non escaping. If a closuse is escaping can 'outlive' the function that is declared in
-        It is used for asychronus operations (basically like a promise in JavaScript)
-        When we use an escaping closure we need to deal also with memory management (that why we use [weak self] on the return of the promise
+     Closures can be escaping or non escaping. If a closuse is escaping can 'outlive' the function that is declared in
+     It is used for asychronus operations (basically like a promise in JavaScript)
+     When we use an escaping closure we need to deal also with memory management (that why we use [weak self] on the return of the promise
      */
 
 
+
+
     // MARK: Followers Call
     func getFollowers(for username: String, page: Int, completed: @escaping(Result<[Follower], GFError>) -> Void) {
         // set endpoint
@@ -160,4 +162,62 @@ class NetworkManager {
         task.resume()
     }
 
+
+
+    // MARK: Avatar Download
+    func downloadImage(from urlString: String, completed: @escaping (UIImage?) -> Void) {
+
+        // CHECK IF IMAGE IS CACHED SO WE DONT DOWNLOD AGAIN
+
+        // convert urlString to NSString
+        let cacheKey = NSString(string: urlString)
+
+        // cacheKey already cached then return it and dont download
+        if let image = cache.object(forKey: cacheKey) {
+            completed(image)
+            return
+        }
+
+        // else go down here and download the image
+
+        // if param is not valid url return
+        guard let url = URL(string: urlString) else {
+            completed(nil)
+            return
+        }
+
+        // make api call
+        let task = URLSession.shared.dataTask(with: url) { [weak self] data, response, error in
+
+            // combine all guard statements into one
+            // if all the following are true go ahead and do things
+            // else completed(nil)
+            guard let self = self,
+                // if calls returns error return
+                error == nil,
+                //if response exists and is not nil and if status code is 200(OK)
+                let response = response as? HTTPURLResponse, response.statusCode == 200,
+                // check if we actually have data returned
+                let data = data,
+                // pass the server data to the image
+                let image = UIImage(data: data) else {
+                    completed(nil)
+                    return
+            }
+
+
+            // save downloaded image to chache
+            self.cache.setObject(image, forKey: cacheKey)
+
+            // if all ok call completed with image
+            completed(image)
+
+        }
+
+        task.resume()
+    }
+
+
+
+
 }