March 14, 2024 - Coding Challenge - Qi Hu

Data/timelineTestOne.json

@@ -0,0 +1,4 @@
+
+{
+    "timeline":[]
+}

OpenTweet/AppDelegate.swift

@@ -12,12 +12,21 @@ import UIKit
 class AppDelegate: UIResponder, UIApplicationDelegate {
 
 	var window: UIWindow?
-
+    var coordinator: MainCoordinator?
 
     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
-		// Override point for customization after application launch.
-		return true
-	}
+        // Override point for customization after application launch.
+        let navController = UINavigationController()
+
+        coordinator = MainCoordinator(navigationController: navController)
+        coordinator?.start()
+
+        window = UIWindow(frame: UIScreen.main.bounds)
+        window?.rootViewController = navController
+        window?.makeKeyAndVisible()
+
+        return true
+    }
 
 	func applicationWillResignActive(_ application: UIApplication) {
 		// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
@@ -40,7 +49,5 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 	func applicationWillTerminate(_ application: UIApplication) {
 		// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
 	}
-
-
 }
 

OpenTweet/Coordinators/Coordinator.swift

@@ -0,0 +1,17 @@
+//
+//  Coordinator.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-11.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+import UIKit
+
+public protocol Coordinator: AnyObject {
+    var childCoordinators: [Coordinator] { get set }
+    var navigationController: UINavigationController { get set }
+
+    func start()
+}

OpenTweet/Coordinators/MainCoordinator.swift

@@ -0,0 +1,28 @@
+//
+//  MainCoordinator.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-13.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+import UIKit
+
+class MainCoordinator: Coordinator {
+    var childCoordinators: [Coordinator] = []
+
+    var navigationController: UINavigationController
+
+    func start() {
+        let tweetFeedCoordinator = TweetFeedCoordinator(navigationController: navigationController)
+        tweetFeedCoordinator.start()
+        childCoordinators.append(tweetFeedCoordinator)
+    }
+
+    init(navigationController: UINavigationController) {
+        self.navigationController = navigationController
+        navigationController.modalTransitionStyle = .crossDissolve
+        navigationController.modalPresentationStyle = .fullScreen
+    }
+}

OpenTweet/Coordinators/TweetFeedCoordinator.swift

@@ -0,0 +1,41 @@
+//
+//  TweetFeedCoordinator.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-13.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+import UIKit
+
+public final class TweetFeedCoordinator: Coordinator {
+    public var childCoordinators: [Coordinator] = []
+
+    public var navigationController: UINavigationController
+
+    public init(navigationController: UINavigationController) {
+        self.navigationController = navigationController
+    }
+
+    public func start() {
+        routeToTimeline()
+    }
+
+    private func routeToTimeline() {
+        let timelineViewModel = TimelineViewModel(
+            timelineService: TimelineService()) { [weak self] tweet in
+                self?.routeToTweetThread(tweet: tweet)
+            }
+        let timelineViewController = TimelineViewController(viewModel: timelineViewModel)
+
+        navigationController.pushViewController(timelineViewController, animated: true)
+    }
+
+    private func routeToTweetThread(tweet: Tweet) {
+        let threadViewModel = ThreadViewModel(tweet: tweet)
+        let threadViewController = ThreadViewController(viewModel: threadViewModel)
+
+        navigationController.pushViewController(threadViewController, animated: true)
+    }
+}

OpenTweet/Info.plist

@@ -22,8 +22,6 @@
 	<true/>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
-	<key>UIMainStoryboardFile</key>
-	<string>Main</string>
 	<key>UIRequiredDeviceCapabilities</key>
 	<array>
 		<string>armv7</string>

OpenTweet/Models/Timeline.swift

@@ -0,0 +1,13 @@
+//
+//  Timeline.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-11.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+
+struct Timeline: Codable {
+    var timeline: [Tweet]
+}

OpenTweet/Models/Tweet.swift

@@ -0,0 +1,31 @@
+//
+//  Tweet.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-11.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+
+final class Tweet: Codable {
+    let id: String
+    let author: String
+    let content: String
+    let date: String
+    let avatar: String?
+    let inReplyTo: String?
+
+    var tweetRepliesTo: Tweet?
+    var tweetReplies: [Tweet]?
+}
+
+extension Tweet: Hashable {
+    static func == (lhs: Tweet, rhs: Tweet) -> Bool {
+        return lhs.id == rhs.id
+    }
+
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(id)
+    }
+}

OpenTweet/Services/TimelineService.swift

@@ -0,0 +1,43 @@
+//
+//  TimelineService.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-12.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+
+protocol TimelineServiceProtocol {
+    func loadTimelineFeed() throws -> Timeline
+}
+
+public enum TimelineServiceError: Error {
+    case filePathError
+    case dataConversionError
+    case decodingError
+}
+
+final class TimelineService: TimelineServiceProtocol {
+    func loadTimelineFeed() throws -> Timeline {
+        let filename = Constants.TimelineService.fileName
+        let fileType = Constants.TimelineService.fileType
+
+        guard let path = Bundle.main.url(forResource: filename, withExtension: fileType, subdirectory: nil) else {
+            throw TimelineServiceError.filePathError
+        }
+
+        do {
+            let data = try Data(contentsOf: path)
+            let decoder = JSONDecoder()
+            do {
+                let result = try decoder.decode(Timeline.self, from: data)
+                return result
+            } catch {
+                throw TimelineServiceError.decodingError
+            }
+        } catch {
+            throw TimelineServiceError.dataConversionError
+        }
+    }
+}

OpenTweet/Shared/Constants.swift

@@ -0,0 +1,50 @@
+//
+//  Constants.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-13.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+
+enum Constants {
+    enum Dimens {
+        static let cellCornerRadius: CGFloat = 5
+        static let padding: CGFloat = 12
+
+        enum FontSize {
+            static let small: CGFloat = 12
+            static let body: CGFloat = 16
+            static let large: CGFloat = 20
+        }
+    }
+
+    enum TweetCell {
+        static let reuseIdentifier = "OpenTweet.TweetCell"
+        static let avatarImageHeight: CGFloat = 50
+        static let avatarImageWidth: CGFloat = 50
+        static let avatarImageCornerRadius: CGFloat = 20
+    }
+
+    enum ThreadHeader {
+        static let reuseIdentifier = "OpenTweet.ThreadHeaderView"
+    }
+
+    enum TimelineService {
+        static let fileName = "timeline"
+        static let fileType = "json"
+    }
+
+    enum TimelineView {
+        static let title = "Timeline"
+    }
+
+    enum ThreadView {
+        static let title = "Thread"
+        static let headerHeight: CGFloat = 40
+        static let originalTweetHeaderTitle = "Tweet Details"
+        static let tweetRepliesToHeaderTitle = "Replies To"
+        static let tweetRepliesHeaderTitle = "Replies"
+    }
+}

OpenTweet/Shared/UIImageViewExtension.swift

@@ -0,0 +1,50 @@
+//
+//  UIImageViewExtension.swift
+//  OpenTweet
+//
+//  Created by HU QI on 2024-03-13.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import UIKit
+
+let imageCache = NSCache<NSString, UIImage>()
+
+extension UIImageView {
+    /// Loads an image from a URL and saves it into an image cache, returns
+    /// the image if already available in the cache.
+    /// - Parameter urlString: String representation of the URL to load the image from
+    /// - Parameter placeholder: An optional placeholder to show while the image is being fetched
+    /// - Returns: A reference to the data task in order to pause, cancel, resume, etc.
+    @discardableResult
+    func loadImageFromURL(urlString: String,
+                          placeholder: UIImage? = nil,
+                          urlSession: URLSession = URLSession.shared,
+                          completionBlock: (() -> Void)? = nil) -> URLSessionDataTask? {
+        self.image = nil
+        let key = NSString(string: urlString)
+        if let cachedImage = imageCache.object(forKey: key) {
+            self.image = cachedImage
+            return nil
+        }
+        if let placeholder = placeholder {
+            self.image = placeholder
+        }
+        guard let url = URL(string: urlString) else {
+            return nil
+        }
+        let task = urlSession.dataTask(with: url) { data, _, _ in
+            DispatchQueue.main.async {
+                if let data = data,
+                   let downloadedImage = UIImage(data: data) {
+                    imageCache.setObject(downloadedImage, forKey: NSString(string: urlString))
+                    self.image = downloadedImage
+                    completionBlock?()
+                }
+
+            }
+        }
+        task.resume()
+        return task
+    }
+}