Changing a collectionView cell changes all of them - ios

Question

This is the code that gets the info from Firebase. It changes the cell's imageView image and the label's text. When it runs the code all of the cells have the same image and label text.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "suggestionCollectionViewCell", for: indexPath) as! SuggestionCollectionViewCell
Database.database().reference().child("users").observeSingleEvent(of: .childAdded) { (snapshot: DataSnapshot) in
if let dict = snapshot.value as? [String : Any] {
let imageURL = dict["imageURL"] as! String
let url = URL(string: imageURL)
let username = dict["username"] as! String
cell.imageView!.sd_setImage(with: url, completed: nil)
cell.usernameLabel.text = username
}
}
return cell
}

Answer 1

Actually for every cell rendering, you are fetching all the users from your Firebase database. Every call's last call is the user you are seeing multiple times. It overrides the previous ones.
To fix you problem you can store your users in an array.
var users = [User]()
To populate this array, you call a similar function like this in your viewDidLoad
func fetchUsers() {
Database.database().reference().child("users").observeSingleEvent(of: .childAdded) { (snapshot: DataSnapshot) in
if let dict = snapshot.value as? [String : Any] {
let user = User()
//set user properties here
users.append(user)
}
}
}
When you fetched all the users, you should reload your collectionView
collectionView.reloadData()
In your cellForItemAt function you can now access the users
let user = users[indexPath.row]
Use the user variable to setup you cell

Answer 2

To remove this problem, firstly you should gather all the data from the firebase in array and then use that array for table view accordingly.