How to call tableview reloadData from another viewcontroller - swift

Question

I am trying to reload the tableview after UIBarbutton is clicked to save a multi line text in UserDefaults.I want to update the tableview cell which is in another view controller after the button is clicked and load the cell but its not working for me.I tried to add an observer but its not working.The cell will show after reopening the app.What i am missing here?
#objc func saveTapped(){
guard let fact = savedFact else {
return
}
let deviceID = UIDevice.current.identifierForVendor!.uuidString
savedValues.append(fact)
if let arr = UserDefaults.standard.array(forKey: deviceID){
var arrvalues = arr as! [String]
if !arrvalues.contains(fact){
arrvalues.append(fact)
UserDefaults.standard.set(arrvalues, forKey:deviceID)
UserDefaults.standard.synchronize()
print (arr)
}
else
{
UserDefaults.standard.set(savedValues, forKey:deviceID)
}
}
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "load"), object: nil)
}
FavoritesViewController
class FavoritesViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {
var savedList = [String]()
private func deleteFavorites(text:String){
let deviceID = UIDevice.current.identifierForVendor!.uuidString
if let arr = UserDefaults.standard.array(forKey: deviceID){
var arrvalues = arr as! [String]
if let index = arrvalues.firstIndex(of:text){
arrvalues.remove(at: index)
savedList.remove(at: index)
UserDefaults.standard.set(arrvalues, forKey:deviceID)
UserDefaults.standard.synchronize()
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
}
}
#IBOutlet var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
tableView.separatorStyle = .none
NotificationCenter.default.addObserver(self, selector: #selector(loadList), name: NSNotification.Name(rawValue: "load"), object: nil)
let deviceID = UIDevice.current.identifierForVendor!.uuidString
savedList = UserDefaults.standard.value(forKey: deviceID) as? [String] ?? []
tableView.register(UINib(nibName: "FavoritesTableViewCell", bundle: nil), forCellReuseIdentifier: FavoritesTableViewCell.identifier)
}
#objc func loadList(notification: NSNotification){
//load data here
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
}
extension FavoritesViewController {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return savedList.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: FavoritesTableViewCell.identifier, for: indexPath) as! FavoritesTableViewCell
cell.cellBgImageView.layer.cornerRadius = 9
cell.factsLabel.text = savedList[indexPath.row]
cell.selectionStyle = .none
return cell
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
deleteFavorites(text: savedList[indexPath.row])
tableView.deleteRows(at: [indexPath], with: .fade)
}
}
}

Answer 1

replace
#objc func loadList(notification: NSNotification){
//load data here
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
as
#objc func loadList(notification: NSNotification){
//load data here
savedList = UserDefaults.standard.value(forKey: deviceID) as? [String] ?? []
DispatchQueue.main.async {
self.tableView.reloadData()
}
}

Answer 2

I know a way, but I don't know if it's the best one.
I always suggest having a shared variable document. In that document, store a variable, which type is FavoritesViewController (in your case).
In FavoritesViewController viewDidLoad(), assign self to the shared variable.
Then, in each other document, subsequently, you can call each method of your FavoritesViewController