How to delete rows from UITableView and update array from UserDefaults in Swift / iOS

Question

I have gone through this to delete rows from UITableView and update array from UserDefaults. But it didn't work.

Here is my code of deleting rows from the tableview. But it is not getting stored in userdefaults

    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            cartArray.remove(at: indexPath.row)
            tableView.deleteRows(at: [indexPath], with: .fade)
            tableView.reloadData()
        }
    }

Please suggest me how to sort this issue. Thanks in advance!

UPDATE :

This is my full code for the cartViewController (of an ecommerce app) :

import UIKit

class CartViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    
    var arrdata = [jsonstruct]()
    var categorydata = [Categories]()
    var imgdata = [Images]()
    
    var cartArray = [CartStruct]()
    
    @IBOutlet var cartTableView: UITableView!
    
    @IBOutlet var totalCount: UILabel!
    @IBOutlet var subtotalPrice: UILabel!
    @IBOutlet var shippingPrice: UILabel!
    @IBOutlet var totalPrice: UILabel!
    @IBOutlet var proceedBtn: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        self.getCartData()
        
        let userDefaults = UserDefaults.standard
        guard let data = userDefaults.array(forKey: "myArrayKey") as? [CartStruct] else {
            return
        }
        cartArray = data
        cartTableView.reloadData()
    }
    
    func getCartData() {
           let defaults = UserDefaults.standard
           if let data = defaults.data(forKey: "cartt") {
               cartArray = try! PropertyListDecoder().decode([CartStruct].self, from: data)
               cartTableView.reloadData()
           }
       }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return cartArray.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "CartCellTableViewCell", for: indexPath) as! CartCellTableViewCell
 
        cell.cartImageView.downloadImage(from: cartArray[indexPath.row].cartItems.images.first?.src ?? "place_holder_image")

        cell.productNameCart.text = cartArray[indexPath.row].cartItems.name
        cell.prodductDescCart.text = cartArray[indexPath.row].cartItems.categories.first?.type
        cell.productPriceCart.text = cartArray[indexPath.row].cartItems.price
        
        cell.addBtn.addTarget(self, action: #selector(add(sender:)), for: .touchUpInside)
        cell.addBtn.tag = indexPath.row
        
        let cartQuantity = cartArray[indexPath.row].cartQuantity
        cell.prodCount.text = "\(cartQuantity)"
        
        if cartQuantity >= 0 {
            cell.subBtn.isUserInteractionEnabled = true;
            cell.subBtn.addTarget(self, action: #selector(sub(sender:)), for: .touchUpInside)
            cell.subBtn.tag = indexPath.row
        } else {
            cell.subBtn.isUserInteractionEnabled = false;
        }
        return cell
    }
    
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            cartArray.remove(at: indexPath.row)
            tableView.deleteRows(at: [indexPath], with: .automatic)
            let userDefaults = UserDefaults.standard
            userDefaults.set(cartArray, forKey: "myArrayKey")
        }
    }
    
    @objc func add(sender: UIButton){
        if cartArray[sender.tag].cartQuantity >= 0 {
            cartArray[sender.tag].cartQuantity += 1
            cartTableView.reloadData()
        }
    }
    
    @objc func sub(sender: UIButton){
        if cartArray[sender.tag].cartQuantity > 0 {
            cartArray[sender.tag].cartQuantity -= 1
            cartTableView.reloadData()
        }
    }
}

Answer 1

You are trying to operate on non-property list object.

You have to follow below mentioned steps:

1. Parse your cart data from UserDefaults according to "[CartStruct]"

2. Check and delete It.

3. Update after deletion to UserDefaults

4. Reload your TableView

    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            cartArray = self.updateCartItems(name: cartArray[indexPath.row].cartItems.name)
            tableView.deleteRows(at: [indexPath], with: .fade)
        }
    }
   

Here, You need to check and delete:

   func updateCartItems(name: String) -> [CartStruct] {
        guard var cartItems = self.getCartData() else { return [] }
        cartItems = cartItems.filter({ $0.cartItems.name != name })
        if let updatedCart = try? PropertyListEncoder().encode(cartItems) {
            UserDefaults.standard.set(updatedCart, forKey: "cartt")
        }
        UserDefaults.standard.set(cartItems.count, forKey: "CountAddedProducts")
        return cartItems
      }