Cells are not displayed in MVVM APP (swift) - ios

Question

I am writing an application to display news from the server. Created a StartController class that only displays data from the ViewModel. There are no warnings in the project, but at startup, a blank screen.
final class StartController: UIViewController {
// MARK: - Private properties
private var viewModel: ViewModel?
private let identifier = "tapeCell"
private let tableView = CustomTableView(frame: .zero)
// MARK: - Lifecycle
override func viewDidLoad() {
super.viewDidLoad()
setUpView()
setUpConstraints()
reloadViewModel()
}
// MARK: - Private functions
private func reloadViewModel() {
viewModel?.configData { [weak self] in
DispatchQueue.main.async {
self?.tableView.reloadData()
}
}
}
private func setUpView() {
view.backgroundColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
tableView.delegate = self
tableView.dataSource = self
tableView.register(UITableViewCell.self, forCellReuseIdentifier: identifier)
view.addSubview(tableView)
}
}
// MARK: - Delegate
extension StartController: UITableViewDelegate {
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100
}
}
// MARK: - DataSource
extension StartController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
viewModel?.numberOfRowsInSection() ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath)
let VM = self.viewModel?.articleAtIndex(indexPath.row)
var content = cell.defaultContentConfiguration()
content.text = VM?.title
content.secondaryText = VM?.author
cell.contentConfiguration = content
return cell
}
}
All the logic takes place inside the ViewModel, downloading data from the network and transferring it to the StartController. But apparently, no data is being transmitted.
final class ViewModel {
// MARK: - Private properties
private let service = TapeService()
private var data: [Articles] = []
// MARK: - Functions
func configData(completion: #escaping() -> ()) {
service.tapeAdd { [weak self] result in
switch result {
case .success(let articles):
self?.data = articles
case .failure(let error):
print(error.localizedDescription)
}
}
}
func numberOfRowsInSection() -> Int {
return data.count
}
func articleAtIndex(_ index: Int) -> ArticleViewModel {
let article = self.data[index]
return ArticleViewModel(article)
}
}
// MARK: - ArticleViewModel
final class ArticleViewModel {
private let article: Articles
init(_ article: Articles) {
self.article = article
}
var title: String {
return self.article.title ?? " "
}
var author: String {
return self.article.author ?? " "
}
}
I would be very grateful if you could tell me what my mistake is and what needs to be done to display the data. Thanks!