Inserting table view row by pressing the button - ios

Question

I created a UITabBarController with two controllers , as first I have a
ViewController with UIButton on it and the second is UITableViewController, how can I by pressing on btn in ViewController insert new row in tableView?
Should it be done with custom delegation ?
Can someone please show quick example
here is my code
import UIKit
class Home: UIViewController {
var delegate: TableViewDelegate?
lazy var addButton : UIButton = {
let button = UIButton(type: .system)
button.setImage(#imageLiteral(resourceName: "plus_photo"), for: .normal)
button.translatesAutoresizingMaskIntoConstraints = false
button.addTarget(self, action: #selector(setupRows), for: .touchUpInside)
return button
}()
#objc func setupRows() {
delegate?.insertingRows()
}
override func viewDidLoad() {
super.viewDidLoad()
delegate = self as? TableViewDelegate
setupRows()
navigationItem.title = "Test"
view.backgroundColor = .white
view.addSubview(addButton)
addButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
addButton.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
addButton.heightAnchor.constraint(equalToConstant: 150).isActive = true
addButton.widthAnchor.constraint(equalToConstant: 150).isActive = true
}
}
import UIKit
protocol TableViewDelegate {
func insertingRows()
}
class TableViewTest: UITableViewController , TableViewDelegate {
var items = ["abc", "abcd", "abcde"]
let cellid = "cellid"
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: cellid)
insertingRows()
}
func insertingRows() {
let indexPath = IndexPath(row: items.count + 1, section: 0)
tableView.insertRows(at: [indexPath], with: .left)
self.tableView.reloadData()
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellid, for: indexPath) as! CustomCell
cell.textLabel?.text = items[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100
}
}
class CustomCell: UITableViewCell {
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupViews() {
}
}

Answer 1

You can use tabBar(_:didSelect:) delegate method in your Home viewController.
Your Home VC :
class Home: UIViewController, UITabBarControllerDelegate {
private var selectedIndex: Int?
override func viewDidLoad() {
super.viewDidLoad()
self.tabBarController?.delegate = self
}
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
if tabBarController.selectedIndex == 1 {
if let secondViewController = viewController as? TableViewTest, let index = selectedIndex {
secondViewController.insertingRows(index: index)
}
}
}
#objc func setupRows() {
selectedIndex = 3
}
}
Your TableViewTest TableViewController :
class TableViewTest: UITableViewController {
func insertingRows(index: Int) {
let indexPath = IndexPath(row: index, section: 0)
tableView.beginUpdates()
tableView.insertRows(at: [indexPath], with: .none)
tableView.endUpdates()
}
}