Swift - table is empty after moving between controllers - ios

Question

I'm updating existing Objective-C app.
There is a structure:
AppDelegate
- creates mainBackgroundView and adding subview with UITabBarController
I have in one "Tab" HistoryViewController:
#objc class HistoryViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let historyTableViewController = HistoryTableViewController()
self.view.addSubview(historyTableViewController.view)
}
}
And HistoryTableViewController:
import UIKit
#objc class HistoryTableViewController: UITableViewController {
// Mark: properties
var historyCalls = [HistoryItem]()
// Mark: private methods
private func loadSimpleHistory() {
let hist1 = HistoryItem(personName: "Test", bottomLine: "text", date: "10:47")
let hist2 = HistoryItem(personName: "Test 2", bottomLine: "text", date: "10:47")
let hist3 = HistoryItem(personName: "Test 3", bottomLine: "text", date: "10:47")
historyCalls += [hist1, hist2, hist3]
}
override func viewDidLoad() {
super.viewDidLoad()
self.loadSimpleHistory()
self.tableView.register(UINib(nibName: "HistoryCallTableViewCell", bundle: nil), forCellReuseIdentifier: "HistoryCallTableViewCell")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return historyCalls.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "HistoryCallTableViewCell", for: indexPath) as? HistoryCallTableViewCell else {
fatalError("Coulnd't parse table cell!")
}
let historyItem = historyCalls[indexPath.row]
cell.personName.text = historyItem.personName
cell.bottomLine.text = historyItem.bottomLine
cell.date.text = historyItem.date
return cell
}
}
When I open the navigation tab with HistoryViewController for the first time, table appers with data. When I click into the table or switch navTab and then go back, table is not there anymore.
When I switch to another app and then go back, table is there again.
How to fix this?
Thank you

Answer 1

Call data method in viewwillappear and reload the table..
override func viewWillAppear() {
super.viewWillAppear()
self.loadSimpleHistory()
self.tableview.reloadData()
}