Can't pass data from cell to UIView - ios

Question

I want to change value of temperature in UIView (blue square), when I tapping on cell in collection view (date). I am trying to use delegate for it, but i can't do it. I want to change value of selectedIndex and pass this value to UIView in viewModel.weather[selectedIndex]
ViewController with collectionView
protocol WeekCityWeatherViewControllerDelegate {
func reloadWeatherData()
}
class WeekCityWeatherViewController: UIViewController {
var delegate: WeekCityWeatherViewControllerDelegate?
...
extension WeekCityWeatherViewController: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 7
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "dateCell", for: indexPath) as! DateWeekWeatherScreenCell
cell.layer.cornerRadius = 5
if selectedIndex == indexPath.row {
cell.backgroundColor = UIColor.blue
cell.dateLabel.textColor = UIColor.white
} else {
cell.backgroundColor = UIColor.white
cell.dateLabel.textColor = UIColor.black
}
if let dateInt = viewModel.weather.first?.week.daily[indexPath.item].dt {
let timeInterval = TimeInterval(dateInt)
let myNSDate = Date(timeIntervalSince1970: timeInterval)
let dateFormatter2 = DateFormatter()
dateFormatter2.dateFormat = "dd/MM E"
dateFormatter2.locale = Locale(identifier: "ru_RU")
let dateString = dateFormatter2.string(from: myNSDate)
cell.dateLabel.text = dateString
}
return cell
}
}
extension WeekCityWeatherViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.frame.width / 5, height: collectionView.frame.height)
}
}
extension WeekCityWeatherViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedIndex = indexPath.row
self.dateCollectionView.reloadData()
delegate?.reloadWeatherData()
}
}
UIView
class DayView: UIView, WeekCityWeatherViewControllerDelegate {
var viewModel: GeneralViewModel
var selectedIndex: Int
var currentIndex: Int
init(frame: CGRect, viewModel: GeneralViewModel, selectedIndex: Int, currentIndex: Int) {
self.viewModel = viewModel
self.selectedIndex = selectedIndex
self.currentIndex = currentIndex
super.init(frame: frame)
createSubviews()
reloadWeatherData()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func reloadWeatherData() {
self.reloadInputViews()
}
private func createSubviews() {
let weekCityWeatherViewController = WeekCityWeatherViewController(viewModel: viewModel, currentIndex: currentIndex)
weekCityWeatherViewController.delegate = self
let tempLabel = UILabel()
tempLabel.textColor = .black
tempLabel.translatesAutoresizingMaskIntoConstraints = false
tempLabel.font = UIFont(name: "Rubik-Regular", size: 30)
if let maxTemp = viewModel.weather[selectedIndex].week.daily[0].temp.max {
tempLabel.text = String(format: "%.0f", maxTemp) + " " + "°"
}
addSubview(tempLabel)
NSLayoutConstraint.activate([
tempLabel.centerXAnchor.constraint(equalTo: centerXAnchor),
tempLabel.topAnchor.constraint(equalTo: topAnchor, constant: 10),
tempLabel.heightAnchor.constraint(equalToConstant: 50),
tempLabel.widthAnchor.constraint(equalToConstant: 50),
])
}
}

Answer 1

create a protocol and send the target cell as a parameter in the trigger method.
Here is the steps;
// 1. protocol and trigger method
protocol ItemTableViewCellDelegate: AnyObject {
func doneButtonTapped(_ cell: ItemTableViewCell)
}
// 2. implement delegate and send the trigger method in your case
class ItemTableViewCell: UITableViewCell {
weak var delegate: ItemTableViewCellDelegate?
//...
}
// MARK: - Implementation
extension ViewController: ItemTableViewCellDelegate {
func doneButtonTapped(_ cell: ItemTableViewCell) {
// 3. find the index of item you tapped the button, via cell as a parameter
guard let indexPath = tableView.indexPath(for: cell) else { return }
var item = MainScreenModel.dummyModel[indexPath.row]
// 4. reload the cell by indexpath
tableView.reloadRows(at: [indexPath], with: .automatic)
}
}