Cant fetch SavedPost - swift

Question

My app has an option to save posts for users to watch later. The code is:
func savedPost(for cell: FirstView) {
guard let indexPath = collectionView.indexPath(for: cell) else { return }
var post = self.posts[indexPath.item]
guard let currentuserId = Auth.auth().currentUser?.uid else { return }
let targetUid = post.user.uid
guard let postId = post.id else { return }
let ref = Database.database().reference().child("save_post").child(currentuserId).child(postId)
if post.hasSaved {
ref.removeValue { (err, _) in
if let _ = err {
showErr(info: NSLocalizedString("failtoUnsave", comment: ""), subInfo: tryLater)
return
}
post.hasSaved = false
self.posts[indexPath.item] = post
self.collectionView.reloadItems(at: [indexPath])
}
} else {
let values = ["userId": targetUid]
ref.updateChildValues(values) { (err, ref) in
if let _ = err {
showErr(info: NSLocalizedString("failtoSave", comment: ""), subInfo: tryLater)
}
post.hasSaved = true
self.posts[indexPath.item] = post
self.collectionView.reloadItems(at: [indexPath])
}
}
}
With this code my firebase database in "save_post" has -> currentUseruId -> postid -> postUserId.
On ProfileController users can view saved Posts from "savedPost" Tab. The code is:
var savedPosts = [Post]()
fileprivate func fetchSaved() {
var userIds = [String]()
var postIds = [String]()
guard let uid = self.user?.uid else { return }
let getIDsRef = Database.database().reference().child("save_post").child(uid)
let query = getIDsRef.queryOrderedByKey()
query.observeSingleEvent(of: .value) { (snapshot) in
let dictionary = snapshot.value as? [String: Any]
dictionary?.forEach({ (key,value) in
guard let dic = value as? [String: String] else { return }
postIds.append(key)
userIds.append(dic["userId"] ?? "")
})
var i = 0
while i < userIds.count {
self.fetchPostsWithUserIDPostID(userID: userIds[i], postID: postIds[i])
i += 1
}
}
}
fileprivate func fetchPostsWithUserIDPostID(userID: String, postID: String) {
let getPostRef = Database.database().reference().child("video_list")
getPostRef.child(userID).child(postID).observeSingleEvent(of: .value, with: { (snapshot) in
guard let dictionary = snapshot.value as? [String: Any] else { return }
let ref = Database.database().reference().child("users").child(userID)
ref.observeSingleEvent(of: .value, with: { (snapshot) in
guard let dict = snapshot.value as? [String: Any] else { return }
let user = User(uid: userID, dictionary: dict)
var post = Post(user: user, dictionary: dictionary)
post.id = postID
guard let currentUserUID = Auth.auth().currentUser?.uid else { return }
Database.database().reference().child("likes").child(postID).child(currentUserUID).observeSingleEvent(of: .value, with: { (snapshot) in
if let value = snapshot.value as? Int, value == 1 {
post.hasLiked = true
} else {
post.hasLiked = false
}
post.hasSaved = true
self.savedPosts.append(post)
self.savedPosts.sort(by: { (p1, p2) -> Bool in
return p1.creationDate.compare(p2.creationDate) == .orderedDescending
})
self.collectionView.reloadData()
})
})
})
}
However, when I click "savedPost" tab, there is no post shown. I don't know where my mistake is. I have all the necessary code under all override func collectionView(....). I believe the error should come from the code listed above. I am sincerely looking for help to resolve this issue. Thanks.

Answer 1

There could be a number of things going on here. It would be good to throw some print statements in there to make sure that 1) the data you're getting back from the database looks like what you expect, and 2) that you're properly parsing it into Post objects. Do you have your cells defined properly for your CollectionView? Also, I don't see where you are defining the data source for the CollectionView.