How to append to an array on another view controller - ios

Question

I have an array in a tableView that shows that contents of that array, and I am able to append values to the array. the problem is that whenever I go to another page, it automatically empties, but I want the values to stay there. Here is my code for the first view controller:
// AddFoodViewController.swift
// grosseries
//
// Created by Amish Tyagi on 6/2/20.
// Copyright © 2020 grosseries. All rights reserved.
//
import UIKit
class AddFoodViewController: UIViewController {
#IBOutlet weak var foodTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func doneTapped(_ sender: Any) {
}
func transitionToNext() {
let homeViewController = storyboard?.instantiateViewController(identifier: "TableViewController") as? TableViewController
view.window?.rootViewController = homeViewController
view.window?.makeKeyAndVisible()
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "toTableViewController") {
let homeViewController = segue.destination as? TableViewController
homeViewController?.food.append(foodTextField.text!)
view.window?.rootViewController = homeViewController
}
}
}
Here is the code for my second view controller:
// TableViewController.swift
// grosseries
//
// Created by Amish Tyagi on 5/29/20.
// Copyright © 2020 grosseries. All rights reserved.
//
import UIKit
class TableViewController: UIViewController{
#IBOutlet var tableView: UITableView!
var food : [String]! = []
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
// Do any additional setup after loading the view.
}
#IBAction func addItemTapped(_ sender: Any) {
transitionToNext()
}
func transitionToNext() {
let nextViewController = storyboard?.instantiateViewController(identifier: "AddFoodViewController") as? AddFoodViewController
view.window?.rootViewController = nextViewController
view.window?.makeKeyAndVisible()
}
}
extension TableViewController : UITableViewDelegate {
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("you tapped me :)")
}
}
extension TableViewController : UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return food.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = food[indexPath.row]
return cell
}
}
Here is a picture of my storyboard layout:
Any Help would be greatly appreciated!

Answer 1

In the storyboard, select your TableViewController storyboard and select Editor->Embed in->Navigation Controller:
Below your tableView (or anywhere else you'd like) add a button with a segue to show the AddFoodViewController.
Now, on your AddFoodViewController add a button to confirm the food you put on textField:
#IBAction func confirmAddedFood(_ sender: Any) {
guard let tableViewVC = navigationController?.viewControllers.first as? TableViewController else { return }
tableViewVC.food.append(foodTextField.text!)
navigationController?.popViewController(animated: true)
}
You don't need the food array on your AddFoodViewController anymore, you still need the one on TableViewController though.
Don't forget to reload the tableView when you go back to it after adding a food, in your TableViewController add:
override func viewWillAppear(_ animated: Bool) {
tableView.reloadData()
}

Answer 2

Your TableViewController:
class TableViewController: UIViewController{
#IBOutlet var tableView: UITableView!
var food: [String] = []
override func viewDidLoad() {
super.viewDidLoad()
// In the case when not using prototype cell.
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
tableView.dataSource = self
}
override func viewWillAppear(_ animated: Bool) {
tableView.reloadData()
}
}
extension TableViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return food.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = food[indexPath.row]
return cell
}
}
And FoodViewController:
class AddFoodViewController: UIViewController {
#IBOutlet weak var foodTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func confirmAddedFood(_ sender: Any) {
guard let tableViewVC = navigationController?.viewControllers.first as? TableViewController else { return }
tableViewVC.food.append(foodTextField.text!)
navigationController?.popViewController(animated: true)
}
}
It's not very cool to just give the already done code, but I think in this case is just a silly mistake, whether from you or me.