How to add label to UITableViewCells before inserting rows? - swift

Question

My goal is to insert a label that says "Loading..." to each visible UITableViewCell before I insert the rows into the tableview.
So far I have the following:
I have a fully functional table view that loads the correct number of cells as well as the information to go in each cell. The code is as follows:
override func viewDidAppear(_ animated: Bool) {
let attributes = [NSAttributedStringKey.foregroundColor: UIColor.white]
refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh", attributes: attributes)
refreshControl.addTarget(self, action: #selector(refresh), for: .valueChanged)
MyChallengesTableView.addSubview(refreshControl) // not required when using UITableViewController
self.BetCreatorUsernameArray.removeAll()
self.BetDescriptionArray.removeAll()
self.UserMoneyInBet.removeAll()
self.BetTotalPoolArray.removeAll()
self.BetEndDateArray.removeAll()
loadData()
self.MyChallengesTableView.reloadData()
}
//refresh table view action
#objc func refresh(refreshControl:UIRefreshControl) {
// Code to refresh table view
//refreshes tableview
self.BetCreatorUsernameArray.removeAll()
self.BetDescriptionArray.removeAll()
self.UserMoneyInBet.removeAll()
self.BetTotalPoolArray.removeAll()
self.BetEndDateArray.removeAll()
loadData()
self.MyChallengesTableView.reloadData()
//stops refreshing
self.refreshControl.endRefreshing()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.BetDescriptionArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "MyChallengesCell", for: indexPath) as! MyChallengesTableViewCell
cell.BetDescriptionOutlet.text = BetDescriptionArray[indexPath.row]
cell.UserMoneyInBetOutlet.text = ("Money In: $" + UserMoneyInBet[indexPath.row])
cell.TotalBetPoolOutlet.text = ("Pool: $" + BetTotalPoolArray[indexPath.row])
cell.BetEndDateOutlet.text = ("End Date: " + BetEndDateArray[indexPath.row])
cell.BetCreatorUsername = BetCreatorUsernameArray[indexPath.row]
cell.betInformation = ["BetDescription" : BetDescriptionArray[indexPath.row],
"BetAmount" : UserMoneyInBet[indexPath.row],
"TotalMoneyInBet" : BetTotalPoolArray[indexPath.row],
"BetEndDate" : BetEndDateArray[indexPath.row],
"BetCreatorUsername" : BetCreatorUsernameArray[indexPath.row]]
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return CGFloat(152)
}
#objc func loadData(){
//get username of current user
self.databaseRef.child("Users").child((Auth.auth().currentUser?.uid)!).child("Username").observeSingleEvent(of: .value, with: {(snapshot) in
self.currentUserUsername = snapshot.value as! String
//make dictionary for each bet that a user is in
self.databaseRef.child("UserBets").child(self.currentUserUsername).observeSingleEvent(of: .value, with: {(snapshot1) in
if snapshot1.exists(){
let UserBetsDictionary = snapshot1.value as! NSDictionary
for (Bet, _) in UserBetsDictionary {
//get bet information from the bets in database
self.databaseRef.child("Bets").child((Bet as? String)!).child("BetInfo").observeSingleEvent(of: .value, with: {(snapshot2) in
let BetInfoDictionary = snapshot2.value as! NSDictionary
self.BetCreatorUsernameArray.append((BetInfoDictionary["Creator Username"] as! String))
self.BetDescriptionArray.append((BetInfoDictionary["BetDescription"] as! String))
self.UserMoneyInBet.append((BetInfoDictionary["BetAmount"] as! String))
self.BetTotalPoolArray.append((BetInfoDictionary["TotalMoneyInBet"] as! String))
self.BetEndDateArray.append((BetInfoDictionary["BetEndTime"] as! String))
//insert the rows
if self.BetCreatorUsernameArray.count != 0 {
self.MyChallengesTableView.insertRows(at: [IndexPath(row:self.BetCreatorUsernameArray.count-1, section:0)], with: UITableViewRowAnimation.automatic)
}
})
}
}
})
})
}
I'm not sure if the code matters too much at this point. In short, I want to add a label before running the function "loadData" in ViewDidAppear and then hide the label once the function is ran and the rows are inserted.

Answer 1

I think it will suit you, just make an extension like this:
extension UITableView {
func startLoading() {
let view = UIView()
separatorStyle = .none
let activityIndicatorView = UIActivityIndicatorView(style: .gray)
activityIndicatorView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(activityIndicatorView)
activityIndicatorView.startAnimating()
activityIndicatorView.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: -10).isActive = true
activityIndicatorView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
let label = UILabel()
label.textColor = UIColor.lightGray
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)
label.text = "Loading..."
label.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: 10).isActive = true
label.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
label.font = UIFont.systemFont(ofSize: 14)
self.backgroundView = view
}
func stopLoading() {
clearTableView()
}
func clearTableView() {
separatorStyle = .singleLine
self.backgroundView = nil
}
}
And after that just invoke method startLoading on your tableView instance before request, and on result from request invoke stopLoading method.