Displaying multiple UICollectionViewCells via enum? - swift

Question

I have an iOS app, written in swift. It's a social platform where the users can post 9 different types of posts (text, image, video, link, audio, poll, chat, etc). I set those using an enum
enum PostType: String {
case image = "image"
case gif = "gif"
case video = "video"
case text = "text"
case link = "link"
case audio = "audio"
case poll = "poll"
case chat = "chat"
case quote = "quote"
}
I'm utilising FirebaseDatabase to store the data. In the DashboardViewController I query the database and get the posts in an array along with the corresponding users, ready to be displayed.
func loadPosts() {
activityIndicator.startAnimating()
Api.Feed.observeFeedPosts(withUserId: Api.Users.CURRENT_USER!.uid) {
post in
guard let userId = post.userUid else { return }
self.fetchUser(uid: userId, completed: {
self.posts.insert(post, at: 0)
self.activityIndicator.stopAnimating()
self.collectionView.reloadData()
})
}
Api.Feed.observeFeedRemoved(withUserId: Api.Users.CURRENT_USER!.uid) { (post) in
self.posts = self.posts.filter { $0.id != post.id } // removed all array elements matching the key
self.users = self.users.filter { $0.id != post.userUid }
self.collectionView.reloadData()
}
}
func fetchUser(uid: String, completed: #escaping () -> Void ) {
Api.Users.observeUsersShort(withId: uid) {
user in
self.users.insert(user, at: 0)
completed()
}
}
Whenever the user creates a new post, it stores PostType.text.rawValue (for example, it gives "text" String) on the database to differentiate between them (either video, photo, text, etc). Now, I have to use the PostType enum to figure out what the post type is and display the corresponding UICollectionViewCell. Now, if its a single cell, it's easy. I can do this and it works:
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return posts.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellName.postTextCVC, for: indexPath) as! PostTextCVC
let user = users[indexPath.row]
let post = posts[indexPath.row]
cell.delegatePostTextCVC = self
cell.user = user
cell.dashboardVC = self
cell.post = post
return cell
}
The problem is, how to use the enum to display the appropriate cell?

Answer 1

Keep a variable PostType variable in your Post class. In cellForItemAt check post type of the post and dequeue respective cell.
Something like this.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let post = posts[indexPath.row]
let type: PostType = post.type // Get the post type eg. text, image etc.
switch type {
case .text:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellName.postTextCVC, for: indexPath) as! PostTextCVC
let user = users[indexPath.row]
cell.delegatePostTextCVC = self
cell.user = user
cell.dashboardVC = self
cell.post = post
return cell
case .image:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellName.postImageCVC, for: indexPath) as! PostImageCVC
return cell
case .video:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellName.postTextCVC, for: indexPath) as! PostVideoCVC
return cell
}
}
If you are using separate nib files for each collection view cell, make sure you register all possible nibs with collection view like this.
collectionView.register(UINib(nibName: "PostTextCVC", bundle: nil), forCellWithReuseIdentifier: CellName.postTextCVC)