Change the UILabel when a static variable changes - swift

Question

I have a CartItem struct where I store the items that I show in a UITableView My UITableView is in CartViewController. I use custom cell for my table view. Here is my custom cell:
class CartItemCell: UITableViewCell {
#IBOutlet weak var productImage: UIImageView!
#IBOutlet weak var productName: UILabel!
#IBOutlet weak var productPrice: UILabel!
#IBOutlet weak var productTotalPrice: UILabel!
#IBOutlet weak var stepper: UIStepper!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
var cellIndex: Int?
var product: CartItem?{
didSet{
// change the cell in table view when first
// initialized and when stepper value is changed
.
.
.
}
#IBAction func stepperValueChanged(_ sender: UIStepper) {
CartItem.cartItems[self.cellIndex!].number = Int(sender.value)
self.product?.number = CartItem.cartItems[self.cellIndex!].number
}
}
In CartViewController I have totalPrice UILabel which gets its value from CartItem.totalPrice static variable. CartItem.totalPrice's value is calculated and changed every time UIStepper in my UITableViewCell is clicked. Here is the summary of CartViewController
class CartViewController: UIViewController{
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var cartLabel: UILabel!
#IBOutlet weak var totalPrice: UILabel!
var items = CartItem.cartItems
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
tableView.delegate = self
tableView.register(UINib(nibName: "CartItemCell", bundle: nil), forCellReuseIdentifier: "ReusableCell")
self.totalPrice.text = String(Int(CartItem.totalPrice))
tableView.reloadData()
}
}
extension CartViewController: UITableViewDataSource{
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ReusableCell", for: indexPath) as! CartItemCell
cell.product = items[indexPath.item]
cell.cellIndex = indexPath.item
return cell
}
}
I want totalPrice label in the CartViewController changed every time CartItem.totalPrice is changed. I change the value of the CartItem.totalPrice in my CartItemCell
Thank you

Answer 1

Use delegate or closures to update value from tableviewcell to viewController
Protocol CartItemProtocol: AnyObject{
func valueUpdated()
}
class CartItemCell: UITableViewCell {
#IBOutlet weak var productImage: UIImageView!
#IBOutlet weak var productName: UILabel!
#IBOutlet weak var productPrice: UILabel!
#IBOutlet weak var productTotalPrice: UILabel!
#IBOutlet weak var stepper: UIStepper!
weak var delegate: CartItemProtocol?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
var cellIndex: Int?
var product: CartItem?{
didSet{
// change the cell in table view when first
// initialized and when stepper value is changed
.
.
.
}
#IBAction func stepperValueChanged(_ sender: UIStepper) {
CartItem.cartItems[self.cellIndex!].number = Int(sender.value)
self.product?.number = CartItem.cartItems[self.cellIndex!].number
self.delegate.valueUpdated()
}
}
And set delegate in cellforRow
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) ->
UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ReusableCell", for: indexPath) as! CartItemCell
cell.product = items[indexPath.item]
cell.cellIndex = indexPath.item
cell.delegate = self
return cell
}
And Update label in delegate conformation
extension CartViewController:CartItemProtocl{
self.totalPrice.text = String(Int(CartItem.totalPrice))
}