Swift 4 and Firebase appending all posts with username and profile image error - swift

Question

I'm having an issue, I can append all the posts into my collection view but the username and profileImage change to whoever the currently logged in user is. Can someone help me figure out how to set it to the user who posted it?
import UIKit
import Firebase
class HomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
var cellId = "cellId"
var filteredPosts = [Post]()
var posts = [Post]()
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(handleUpdateFeed), name: PostController.updateFeedNotificationName, object: nil)
collectionView?.backgroundColor = UIColor(red: 240/255, green: 240/255, blue: 240/255, alpha: 1)
collectionView?.register(HomePostCell.self, forCellWithReuseIdentifier: cellId)
let refreshControl = UIRefreshControl()
refreshControl.addTarget(self, action: #selector(handleRefresh), for: .valueChanged)
collectionView?.refreshControl = refreshControl
setupNavigationItems()
fetchPosts()
}
#objc func handleUpdateFeed() {
handleRefresh()
}
fileprivate func fetchPosts() {
guard let uid = FIRAuth.auth()?.currentUser?.uid else { return }
FIRDatabase.fetchUserWithUID(uid: uid) { (user) in
self.fetchPostsWithUser(user: user)
}
}
fileprivate func fetchPostsWithUser(user: User) {
let ref = FIRDatabase.database().reference().child("posts")
ref.observe(.childAdded, with: { (snapshot) in
guard let dictionaries = snapshot.value as? [String: Any]
else { return }
dictionaries.forEach({ (key, value) in
guard let userDictionary = value as? [String: Any] else { return }
var post = Post(user: user, dictionary: userDictionary)
self.posts.append(post)
})
self.posts.sort(by: { (post1, post2) -> Bool in
return post1.creationDate.compare(post2.creationDate) == .orderedDescending
})
self.collectionView?.reloadData()
}) { (err) in
print("Failed to fetch posts.",err)
}
}
#objc func handleRefresh() {
self.posts.removeAll()
self.fetchPosts()
DispatchQueue.global(qos: .background).async {
self.collectionView?.reloadData()
self.collectionView?.refreshControl?.endRefreshing()
}
}
func setupNavigationItems() {
navigationItem.title = "Events"
navigationItem.leftBarButtonItem = UIBarButtonItem(image: #imageLiteral(resourceName: "download").withRenderingMode(.alwaysOriginal), style: .plain, target: self, action: #selector(handleFilter))
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return posts.count
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: 200)
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! HomePostCell
cell.post = posts[indexPath.item]
return cell
}
}
import UIKit
class HomePostCell: UICollectionViewCell {
var post: Post? {
didSet{
usernameLabel.text = post?.user.username
guard let profileImageUrl = post?.user.profileImageUrl else { return }
userProfileImageView.loadImage(urlString: profileImageUrl)
setupCaptionText()
setupDateLabel()
}
}
let userProfileImageView: CustomImageView = {
let iv = CustomImageView()
iv.clipsToBounds = true
iv.contentMode = .scaleAspectFill
return iv
}()
let usernameLabel: UILabel = {
let label = UILabel()
label.font = UIFont.boldSystemFont(ofSize: 14)
return label
}()
let captionLabel: UILabel = {
let label = UILabel()
label.numberOfLines = 0
label.backgroundColor = .white
return label
}()
let dateLabel: UILabel = {
let label = UILabel()
label.font = UIFont.boldSystemFont(ofSize: 14)
return label
}()
let optionsButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("•••", for: .normal)
button.setTitleColor(UIColor.black, for: .normal)
return button
}()
fileprivate func setupCaptionText() {
guard let post = self.post else { return }
let attributedText = NSMutableAttributedString(string: " \(post.caption)", attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14)])
captionLabel.attributedText = attributedText
}
fileprivate func setupDateLabel() {
guard let post = self.post else { return }
let timeAgoDisplay = post.creationDate.timeAgoDisplay()
let attributedText = NSMutableAttributedString(string: timeAgoDisplay, attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14), NSAttributedStringKey.foregroundColor: UIColor.gray])
dateLabel.attributedText = attributedText
}
override init(frame: CGRect) {
super.init(frame: frame)
addSubview(userProfileImageView)
userProfileImageView.anchor(top: topAnchor, left: leftAnchor, bottom: nil, right: nil, paddingTop: 8, paddingLeft: 8, paddingBottom: 5, paddingRight: 0, width: 40, height: 40)
userProfileImageView.layer.cornerRadius = 40 / 2
backgroundColor = .white
addSubview(usernameLabel)
usernameLabel.anchor(top: topAnchor, left: userProfileImageView.rightAnchor, bottom: nil, right: nil, paddingTop: 12, paddingLeft: 8, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
addSubview(captionLabel)
captionLabel.anchor(top: userProfileImageView.bottomAnchor, left: leftAnchor, bottom: nil, right: rightAnchor, paddingTop: 10, paddingLeft: 8, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
addSubview(optionsButton)
optionsButton.anchor(top: topAnchor, left: nil, bottom: nil, right: rightAnchor, paddingTop: 5, paddingLeft: 0, paddingBottom: 0, paddingRight: 10, width: 0, height: 0)
addSubview(dateLabel)
dateLabel.anchor(top: nil, left: leftAnchor, bottom: bottomAnchor, right: nil, paddingTop: 0, paddingLeft: 8, paddingBottom: 5, paddingRight: 0, width: 0, height: 0)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
import Foundation
struct User {
var uid: String
let username: String
let profileImageUrl: String
init(uid: String, dictionary: [String: Any]) {
self.uid = uid
self.username = dictionary["usernames"] as? String ?? ""
self.profileImageUrl = dictionary["profileImageUrl"] as? String ?? ""
}
}
import Foundation
struct Post {
var id: String?
let user: User
let caption: String
let creationDate: Date
init(user: User, dictionary: [String: Any]) {
self.user = user
self.caption = dictionary["caption"] as? String ?? ""
let secondsFrom1970 = dictionary["creationDate"] as? Double ?? 0
self.creationDate = Date(timeIntervalSince1970: secondsFrom1970)
}
}

Answer 1

This code here:
fileprivate func fetchPosts() {
guard let uid = FIRAuth.auth()?.currentUser?.uid else { return }
FIRDatabase.fetchUserWithUID(uid: uid) { (user) in
self.fetchPostsWithUser(user: user)
}
}
You're basically making a query based on the currentUser?.uid and not on the user that created the post. You're passing that to the fileprivate func fetchPostsWithUser(user: User) hence it retrieves the same logged in user.
It actually should pass the user.uid stored for each post on the database (unless you want to pull out the posts for the currentUser and display those.
Each post at the moment of posting needs to store the user uid and store that on the database. Then make query to get those posts based on the uid of the user. And cache your users in an array just like you did with your posts.
UPDATED:
class Post {
var id : String?
var title : String?
var content : String?
var userUid : String?
static func transformDataToPost (dictionary: [String : Any], key: String) -> Post {
let post = Post()
post.id = key // this is the snapshot.key that you get
post.userUid = dictionary["userUid"] as? String
post.title = dictionary["title"] as? String
post.content = dictionary["content"] as? String
return
}
Now, when observing the post to get data back from Firebase I'm using it a little more structured, in another class, ie, I have separate PostApi class where I deal with all API requests, not in the UIViewController itself, but the idea is the same.
var REF_POSTS = Database.database().reference().child("posts")
func observePost(withId id: String, completion: #escaping (Post) -> Void) {
REF_POSTS.child(id).observeSingleEvent(of: .value, with: { snapshot in
if let dictionary = snapshot.value as? [String : Any] {
let post = Post.transformDataToPost(dictionary: dictionary, key: snapshot.key)
completion(post)
}
})
}
For sending the data to FirebaseDatabase I do it the following way:
static func sendPostDataToDatabase ( title: String?,
content: String?,
onSuccess: #escaping () -> Void,
onError: #escaping (_ errorMessage: String?) -> Void) {
let newPostId = Api.Post.REF_POSTS.childByAutoId().key // THIS creates the new ID of a post, it's just a dynamic way to get a unique post ID , you can also use NSUUID().uuidString which will give you a unique string
// the definition of `uuidString` is: A string containing a formatted UUID for example E621E1F8-C36C-495A-93FC-0C247A3E6E5F.
let newPostReference = Api.Post.REF_POSTS.child(newPostId)
// MARK: - TIMESTAMP FEATURE
let timestamp = Int(Date().timeIntervalSince1970)
var newPostDict = [ "userUid" : Api.Users.CURRENT_USER!.uid,
"title" : title as Any,
"content" : content as Any,
"timestamp" : timestamp
] as [String : Any]
newPostReference.setValue(newPostDict) { (error, databaseRef) in
if error != nil {
onError(error!.localizedDescription)
return
}
else {
onSuccess(newShipId, photosArray[0])
}
}