Error in my code when trying to storeData - ios

Question

I get
Referencing instance method 'encode' on 'Array' requires that '(item: String?, price: String?, salesPrice: String?)' conform to 'Encodable' "
this error in the storeData() function. Did I even save the tuple correctly in user defaults? If anyone can help that would be great!Any help is appreciated!
import UIKit
let defaults = UserDefaults(suiteName: "com.Saving.Data")
struct Product: Codable {
var title: String
var price: String
var salePrice: String
}
class ViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var items: [(item: String?, price: String?, salesPrice: String?)] = []
override func viewDidLoad() {
super.viewDidLoad()
getData()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
getData()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(true)
storeData()
}
override var prefersStatusBarHidden: Bool {
return true
}
#IBAction func addButtonTapped(_ sender: Any) {
let alert = UIAlertController(title: "Product Information", message: nil, preferredStyle: .alert)
alert.addTextField { (itemTF) in
itemTF.placeholder = "Item"
}
alert.addTextField { (textField) in
textField.placeholder = "Price"
}
alert.addTextField { (textField) in
textField.placeholder = "Sale Price"
}
let action = UIAlertAction(title: "Add", style: .default) { (_) in
var product : (item: String, price: String, salesPrice: String) = ("","","")
if let textField1 = alert.textFields?[0], let text = textField1.text {
print(text)
product.item = text
}
if let textField2 = alert.textFields?[1], let text = textField2.text {
print(text)
product.price = text
}
if let textField3 = alert.textFields?[2], let text = textField3.text {
print(text)
product.salesPrice = text
}
self.add(product)
}
alert.addAction(action)
present(alert, animated: true)
storeData()
}
func add(_ product: (item: String, price: String, salesPrice: String)) {
let index = 0
items.insert(product, at: index)
let indexPath = IndexPath(row: index, section: 0)
tableView.insertRows(at: [indexPath], with: .left)
storeData()
}
func storeData() {
if let data = try? PropertyListEncoder().encode(items) {
UserDefaults.standard.set(data, forKey: "savedData")
}
}
func getData() {
if let data = UserDefaults.standard.data(forKey: "savedData") {
let items = try! PropertyListDecoder().decode([Product].self, from: data)
print(items)
}
}
}
extension ViewController: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell()
let product = items[indexPath.row]
cell.textLabel?.text = product.item
print(product.price ?? "")
print(product.salesPrice ?? "")
cell.contentView.backgroundColor = UIColor(red:0.92, green:0.92, blue:0.92, alpha:1.0)
cell.textLabel?.textColor = UIColor(red:0.13, green:0.13, blue:0.13, alpha:1.0)
tableView.separatorColor = UIColor(red:0.92, green:0.92, blue:0.92, alpha:1.0)
return cell
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
guard editingStyle == .delete else { return }
items.remove(at: indexPath.row)
tableView.reloadData()
storeData()
}
}

Answer 1

As already mentioned in the comments it's incomprehensible why you use an extra tuple with the same design as your struct Product. This causes your problems.
So get rid of the tuple.
Declare items
var items = [Product]()
Replace the alert action with
let action = UIAlertAction(title: "Add", style: .default) { _ in
let item = alert.textFields?[0].text ?? ""
let price = alert.textFields?[1].text ?? ""
let salesPrice = alert.textFields?[2].text ?? ""
let product = Product(item: item, price: price, salesPrice: salesPrice)
self.addProduct(product)
}
Replace add with
func addProduct(_ product: Product) {
let index = 0
items.insert(product, at: index)
let indexPath = IndexPath(row: index, section: 0)
tableView.insertRows(at: [indexPath], with: .left)
storeData()
}
Replace getData with
func getData() {
if let data = UserDefaults.standard.data(forKey: "savedData") {
do {
items = try PropertyListDecoder().decode([Product].self, from: data)
print(items)
tableView.reloadData()
} catch { print(error) }
}
}
Side note: Be aware that the code saves the data in standard UserDefaults, not in your custom suite.
And finally – not related to the issue – to get a nice animation in tableView:commit editingStyle: replace
tableView.reloadData()
with
tableView.deleteRows(at: [indexPath], with: .fade)