Codepath-Twitter-Clone/Twitter-Clone

Twitter

Table of Contents

1. Overview
2. Product Spec
3. Wireframes
4. Schema

Overview

Description

The team is building an MVP version of Twitter with strictly Swift UI using the MVVM architecture. We will be building this completely from scratch, starting with the User Interface skeleton, and working our way up to integrating our API with Firebase and data models. We will be building all the core components of a social network. This includes following users, uploading/liking tweets, direct messaging, creating a user profile, and registering users.

App Evaluation

• Social
• UI/UX for mobile iOS experience
• A service for friends, family, and coworkers to stay connected through the exchange of quick, frequent messages
• 353 million active users
• Twitter audience most receptive, valuable for its influence, and brand conscious
• Very mature technology

Product Spec

1. User Stories (Required and Optional)

Required Must-have Stories

• Following users
• Viewing tweets
• Uploading/liking/commenting tweets
• Implement user profile
• Log-in/sign-up users
• Search users

Optional Nice-to-have Stories

• Direct messaging
• Edit user profile

2. Screen Archetypes

• Login
  • Login
• Signup
  • Signup
• Main
  • Viewing tweets
  • Following users
  • liking tweets
• Profile
  • Creating/editing a user profile
• Post
  • Uploading tweets
• Tweet
  • Viewing tweets details
  • Viewing tweets comments
  • Commenting tweets
  • Following users
  • liking tweets

3. Navigation

Tab Navigation (Tab to Screen)

• No tab navigation needed.

Flow Navigation (Screen to Screen)

• Login
  • Main
• Signup
  • Login
• Main
  • Post
  • Profile
  • Tweet
• Profile
  • Main
• Post
  • Tweet
• Tweet
  • Main

Schema

Models

User

Property	Type	Description
id	String	unique id for the user
username	String	username
profileImageUrl	String	URL to profile image
fullname	String	full name
email	String	email
stats	UserStats	user statistics
bio	String	bio
isFollowed	Bool	if the user is already followed
isCurrentUser	Bool	if this instance is current user

UserStats

Property	Type	Description
followers	Int	number of followers
following	Int	number of owner's followings

Tweet

Property	Type	Description
id	String	unique id for the user
username	String	username
profileImageUrl	String	URL to profile image
fullname	String	full name
caption	String	caption
likes	Int	user statistics
uid	String	unique id for the message
timeStamp	TimeStamp	time of tweet
replyingTo	String	receiver ID

Message

Property	Type	Description
id	String	unique id for the message
user	User	user
toId	String	receiver ID
fromId	String	sender ID
isFromCurrentUser	Bool	if sender is current user
timeStamp	TimeStamp	time of message

Networking

• Login

  • (Get) get user info

      func login(withEmail email: String, password: String) {
        Auth.auth().signIn(withEmail: email, password: password) { result, error in
            if let error = error {
                print("DEBUG: Failed to login: \(error.localizedDescription)")
                return
            }
            
            self.userSession = result?.user
            self.fetchUser()
        }
    }

• Signup

  • (Post) post user info

       func registerUser(email: String, password: String, username: String,
                     fullname: String, profileImage: UIImage) {
       
       guard let imageData = profileImage.jpegData(compressionQuality: 0.3) else { return }
       let filename = NSUUID().uuidString
       let storageRef = Storage.storage().reference().child(filename)
       
       storageRef.putData(imageData, metadata: nil) { _, error in
           if let error = error {
               print("DEBUG: Failed to upload image \(error.localizedDescription)")
               return
           }
                       
           storageRef.downloadURL { url, _ in
               guard let profileImageUrl = url?.absoluteString else { return }
               
               Auth.auth().createUser(withEmail: email, password: password) { result, error in
                   if let error = error {
                       print("DEBUG: Error \(error.localizedDescription)")
                       return
                   }
                   
                   guard let user = result?.user else { return }
                   
                   let data = ["email": email,
                               "username": username.lowercased(),
                               "fullname": fullname,
                               "profileImageUrl": profileImageUrl,
                               "uid": user.uid]
                   
                   Firestore.firestore().collection("users").document(user.uid).setData(data) { _ in
                       self.userSession = user
                       self.fetchUser()
                   }
               }
           }
       }
     }

• Main

  • (Get) get main page tweets

     func fetchTweets() {
       guard let uid = AuthViewModel.shared.userSession?.uid else { return }
       var tweets = [Tweet]()
       COLLECTION_USERS.document(uid).collection("user-feed").getDocuments { snapshot, _ in
           guard let documents = snapshot?.documents else { return }
                       
           documents.forEach { document in
               COLLECTION_TWEETS.document(document.documentID).getDocument { snapshot, _ in
                   guard let data = snapshot?.data() else { return }
                   tweets.append(Tweet(dictionary: data))
                   
                   if tweets.count == documents.count {
                       self.tweets = tweets.sorted(by: { $0.timestamp.dateValue() > $1.timestamp.dateValue() })
                   }
               }
           }
       }
    }

  • (Post) sign out

     func signOut() {
         userSession = nil
         user = nil
         try? Auth.auth().signOut()
     }

• Profile

  • (Get) get user details

     func fetchUserStats() {
       guard let user = self.user else { return }
       UserService.fetchUserStats(user: user) { stats in
           self.user?.stats = stats
       }
     }

• Post

  • (Post) post user tweet

    private func upload(caption: String, type: TweetUploadType) {
       guard let user = AuthViewModel.shared.user else { return }
       let docRef = documentReference(forUploadType: type)
       
       var data: [String: Any] = ["uid": user.id,
                                  "caption": caption,
                                  "fullname": user.fullname, "timestamp": Timestamp(date: Date()),
                                  "username": user.username,
                                  "profileImageUrl": user.profileImageUrl,
                                  "likes": 0,
                                  "id": docRef.documentID]
       
       switch type {
       case .reply(let tweet):
           data["replyingTo"] = tweet.username
           
           docRef.setData(data) { _ in
               let userRepliesRef = COLLECTION_USERS.document(user.id).collection("user-replies").document(docRef.documentID)
               userRepliesRef.setData(data) { _ in
                   self.isPresented = false
                   NotificationViewModel.uploadNotification(toUid: tweet.uid, type: .reply, tweet: tweet)
               }
           }
       case .tweet:
           docRef.setData(data) { _ in
               self.isPresented = false 
           }
       }
    }

• Tweet

  • (Post) tweet interactions like liking, following, commenting

    func likeTweet() {
       guard let uid = AuthViewModel.shared.userSession?.uid else { return }
       let tweetLikesRef = COLLECTION_TWEETS.document(tweet.id).collection("tweet-likes")
       let userLikesRef = COLLECTION_USERS.document(uid).collection("user-likes")
       
       COLLECTION_TWEETS.document(tweet.id).updateData(["likes": tweet.likes + 1]) { _ in
           tweetLikesRef.document(uid).setData([:]) { _ in
               userLikesRef.document(self.tweet.id).setData([:]) { _ in
                   self.didLike = true
                   
                   NotificationViewModel.uploadNotification(toUid: self.tweet.uid, type: .like, tweet: self.tweet)
               }
           }
       }
    }

  • (Delete) revert actions like liking, following

    func unlikeTweet() {
       guard let uid = AuthViewModel.shared.userSession?.uid else { return }
       let tweetLikesRef = COLLECTION_TWEETS.document(tweet.id).collection("tweet-likes")
       let userLikesRef = COLLECTION_USERS.document(uid).collection("user-likes")
       
       COLLECTION_TWEETS.document(tweet.id).updateData(["likes": tweet.likes - 1]) { _ in
           tweetLikesRef.document(uid).delete { _ in
               userLikesRef.document(self.tweet.id).delete { _ in
                   self.didLike = false
                   
                   NotificationViewModel.deleteNotification(toUid: self.tweet.uid, type: .like, tweetId: self.tweet.id)
               }
           }
       }
    }

  • (Get) get tweet details

     func fetchUserTweets() {
       COLLECTION_TWEETS.whereField("uid", isEqualTo: user.id).getDocuments { snapshot, _ in
           guard let documents = snapshot?.documents else { return }
           self.userTweets = documents.map({ Tweet(dictionary: $0.data()) })
       }
    }