Firestore chat application displaying messaged users error - swift

Question

I have added chatting/messaging to my application. I can go to a users profile, select message and message them.
I also added a tab that show all the users I messaged which is in a table view and you can click a user and see messages between you and them.
The issue happens when I open this tab to see the users Ive messaged when I've messaged more than 10 users. The simulator crashes and I get this error:
"Thread 1: Exception: "Invalid Query. 'in' filters support a maximum of 10 elements in the value array."
here is my code:
import UIKit
import FirebaseFirestore
class MessagingVC: UIViewController {
#IBOutlet weak var tableView: UITableView! { didSet {
tableView.tableFooterView = UIView()
tableView.contentInset.top = 10
}}
#IBOutlet weak var noDataLabel: UILabel!
private let db = Firestore.firestore()
var users = [AppUser]()
var user: AppUser {
return UserManager.currentUser!
}
private var lastMessageDict: [String: Date]?
private var unreadMessageDict: [String: Bool]?
var chatListener: ListenerRegistration?
override func viewDidLoad() {
super.viewDidLoad()
getChats()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
noDataLabel.isHidden = true
// remove any blocked users when entering the screen.
users.removeAll() { self.user.blockedUsers?.contains($0.uid) == true }
// filter hidden users
users = users.filter { $0.isHidden ?? false == false }
tableView.reloadData()
// getChats()
}
// Get all users id that the current user has been chating with.
func getChats() {
let chatCollection = db.collection("chat")
chatListener = chatCollection.whereField("participants", arrayContains: user.uid).addSnapshotListener { [unowned self] (querySnapshot, error) in
guard error == nil else {
print(error!.localizedDescription)
return
}
var userChatIds = [String]()
self.lastMessageDict = [String: Date]()
self.unreadMessageDict = [String: Bool]()
for chat in querySnapshot?.documents ?? [] {
let chatData = chat.data()
if let participants = chatData["participants"] as? [String] {
for particiant in participants {
if particiant != self.user.uid,
!(self.user.blockedUsers?.contains(particiant) == true),
!userChatIds.contains(particiant) {
userChatIds.append(particiant)
if let lastMessageDate = chatData["last message"] as? Timestamp {
self.lastMessageDict![particiant] = lastMessageDate.dateValue()
}
if let unreadMessageDict = chatData["unread message"] as? [String: Bool],
let unreadMesage = unreadMessageDict[self.user.uid] {
self.unreadMessageDict![particiant] = unreadMesage
}
}
}
}
}
if !userChatIds.isEmpty {
self.getChatsInfo(chatIds: userChatIds)
} else {
self.tableView.reloadData()
self.noDataLabel.isHidden = self.users.count > 0
}
}
}
func getChatsInfo(chatIds: [String]) {
getUsersForChat(chatIds) { (users, error) in
guard error == nil else {
print(error?.localizedDescription ?? "")
return
}
for user in users {
if let index = self.users.firstIndex(of: user) {
self.users[index] = user
} else {
self.users.append(user)
}
}
// self.users = users
self.users.sort { (first, second) -> Bool in
let firstDate = self.lastMessageDict?[first.uid]
let secondDate = self.lastMessageDict?[second.uid]
if firstDate == nil { return false }
else if secondDate == nil { return true }
else {
return firstDate! > secondDate!
}
}
self.users = self.users.filter { $0.isHidden ?? false == false }
self.tableView.reloadData()
self.noDataLabel.isHidden = self.users.count > 0
}
}
func getUsersForChat(_ ids: [String], completion:#escaping (_ users: [AppUser], _ error: Error?)->()) {
var allUsers = [AppUser]()
let allids = self.users.map { $0.uid }
let ids = ids.filter { !allids.contains($0) }
if ids.count == 0 {
completion(allUsers, nil)
return
}
var error: Error?
let userCollection = db.collection("users")
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
userCollection.whereField("uid", in: ids).getDocuments {querySnapshot,err in
error = err
var users = [AppUser]()
for document in querySnapshot?.documents ?? [] {
if let restaurant = Restaurant(snapshot: document) {
users.append(restaurant)
}
}
allUsers.append(contentsOf: users)
dispatchGroup.leave()
}
dispatchGroup.enter()
let userCollection2 = db.collection("users2")
userCollection2.whereField("uid", in: ids).getDocuments {querySnapshot,err in
error = err
var users = [AppUser]()
for document in querySnapshot?.documents ?? [] {
if let user = AppUser(snapshot: document) {
users.append(user)
}
}
allUsers.append(contentsOf: users)
dispatchGroup.leave()
}
dispatchGroup.notify(queue: DispatchQueue.main) {
completion(allUsers, error)
}
}
deinit {
chatListener?.remove()
}
}
extension MessagingVC: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return users.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "MessageCell", for: indexPath) as! MessagingTableViewCell
let user = users[indexPath.row]
cell.nameLabel.text = user.firstName + " " + user.lastName
if let unreadMessage = unreadMessageDict?[user.uid],
unreadMessage == true {
cell.unreadMessageIndicatorLabel.isHidden = false
} else {
cell.unreadMessageIndicatorLabel.isHidden = true
}
cell.photoImageView.image = nil
user.getProfileImage { (image) in
DispatchQueue.main.async {
if let cell = tableView.cellForRow(at: indexPath) as? MessagingTableViewCell {
cell.photoImageView.image = image
}
}
}
if let rest = user as? Restaurant {
cell.categoryImageView.image = UIImage(named: rest.Categories1)
}
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
let user = users[indexPath.row]
// unreadMessageDict?[user.uid] = false
performSegue(withIdentifier: "messagingToChatSegue", sender: user)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "messagingToChatSegue" {
let chatVC = segue.destination as! ChatViewController
let otherUser = sender as! AppUser
chatVC.currentUser = user
chatVC.otherUser = otherUser
chatVC.channelId = ClickedResturantVC.generateIdForMessages(user1Id: user.uid, user2Id: otherUser.uid)
}
}
}
Here is a picture of the error I am getting
Here is a picture of my Firestore database

Answer 1

The error message is telling you that Firestore doesn't support more than 10 items in the ids array that you pass to this query filter:
userCollection.whereField("uid", in: ids)
According to the documentation for this sort of query:
Note the following limitations for in and array-contains-any:
in and array-contains-any support up to 10 comparison values.
If you need more than 10, you will need to batch them into multiple queries.