Can't return a value from UITextField to UILabel in UITableViewCell as subviews - ios

Question

I made a UITextfield to receive the data from user.
I want to convert a value from UITextField to UILabel.
I did it in simple UIView, which has only two object, UITextField and UILabel.
This is the code that works.
class ViewController: UIViewController, UITextFieldDelegate {
let inputNumber = UITextField(frame: CGRect(x: 150.0, y: 100.0, width: 200.0, height: 50.0))
let outputNumber = UILabel(frame: CGRect(x: 150.0, y: 200.0, width: 200.0, height: 50.0))
let toolBarKeyBoard = UIToolbar()
let flexibleSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: nil, action: #selector(donePressed))
var result : String!
override func viewDidLoad() {
super.viewDidLoad()
calculatePrice()
}
func calculatePrice () {
priceInputLabel.keyboardType = .numberPad
priceInputLabel.clearButtonMode = .whileEditing
self.view.addSubview(priceInputLabel)
toolBarKeyBoard.sizeToFit()
toolBarKeyBoard.setItems([flexibleSpace, doneButton], animated: false)
priceInputLabel.inputAccessoryView = toolBarKeyBoard
}
#objc func donePressed() {
view.endEditing(true)
result = inputNumber.text!
let convertedNumber = (result as NSString).doubleValue
if Int(inputNumber.text!) == nil {
outputNumber.text = String("Nil")
} else {
outputNumber.text = String(Int(convertedNumber * 0.85))
}
}
}
But in other case, down below, the problem is UITextField and UILabel are in the UITableViewCell as subviews.
I made a 3 swift files. 2 files are UITableViewCell subclasses, and 1 file is a UITableView class.
1. FruitTableViewCell : UITableViewCell subclass
class FruitTableViewCell: UITableViewCell, UITextFieldDelegate {
var fruitsTextField = UITextField()
let toolBarKeyBoard = UIToolbar()
let flexibleSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: nil, action: #selector(donePressed))
var result : String!
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.contentView.addSubview(fruitsTextField)
}
override func layoutSubviews() {
super.layoutSubviews()
fruitsTextField.frame = CGRect(x: 250, y: 7.5, width: 100, height: 30)
fruitsTextField.textColor = UIColor(red: CGFloat(242/255.0), green: CGFloat(56/255.0), blue: CGFloat(90/255.0), alpha: 1.0)
fruitsTextField.keyboardType = .numberPad
fruitsTextField.clearButtonMode = .whileEditing
toolBarKeyBoard.sizeToFit()
fruitsTextField.inputAccessoryView = toolBarKeyBoard
toolBarKeyBoard.setItems([flexibleSpace, doneButton], animated: false)
}
#objc func donePressed() {
fruitTextField.endEditing(true)
}
}
2. AnotherFruitTableViewCell : UITableViewCell subclass
class AnotherFruitTableViewCell: UITableViewCell {
var fruitsTextLabel = UILabel()
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.contentView.addSubview(fruitsTextLabel)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
fruitsTextLabel.backgroundColor = UIColor.brown
fruitsTextLabel.frame = CGRect(x: 250.0, y: 7.5, width: 100.0, height: 30.0)
}
}
3. TableViewController : UITableViewController class
class TableViewController: UITableViewController, UITextFieldDelegate {
let fruitsComponents: [String] = ["Apple", "Banana", "Grape", "Pear"]
let cellReuseidentifier = "cell"
let anotherCellReuseidentifier = "anotherCell"
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(FruitTableViewCell.self, forCellReuseIdentifier: cellReuseidentifier)
tableView.register(AnotherFruitTableViewCell.self, forCellReuseIdentifier: anotherCellReuseidentifier)
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return fruitsComponents.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseidentifier, for: indexPath) as! FruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row]
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: anotherCellReuseidentifier, for: indexPath) as! AnotherFruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row]
return cell
}
}
}
The fruitsTextField and fruitsTextLabel is not in the same class like in the first example code.
So, I cannot call both instances and calculate a value in ViewController class. Of course, cannot return a calculated value.
And, I'm not sure I can return after touching a done button to get a value from UITextField to UILabel, because the cells which is the super view of subview(UITextField and UILabel) are reproduced. I'm confusing touching a done button occurs dequeueing cells again.
How can I return a value from UITextField to UILabel in UITableViewCell?
Thanks!

Answer 1

If I understand correctly you want to change some parameter of one cell based on action in another cell (actually the fact that these cells are of different classes is not important to that matter). ViewController will be in that case intermediary, so you need to make cells to communicate with ViewController. For communication between two objects one usually uses delegate or closure pattern.
In that case I would use closure. So, when you instantiate the cell with TextField ViewController tells Cell what to do when Done is pressed. To achieve that:
add var didEntered: ((_ text: String)->())? to FruitTableViewCell
add didEntered?(fruitsTextField.text ?? "") to #objc func donePressed()
add (the code updates the second row based on textfield value - just for a example)
cell.didEntered = {text in
self.fruitsComponents[1] = text
self.tableView.reloadRows(at: [IndexPath(row: 1, section: 0)], with: UITableViewRowAnimation.none)}
to override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
On the way I corrected some mistakes to make it work, so the complete code is below.
Upd 1
import UIKit
class ViewController: UITableViewController, UITextFieldDelegate {
var fruitsComponents: [String] = ["Apple", "Banana", "Grape", "Pear"]
var fruitsLabels: [String] = ["", "", "", ""]
let cellReuseidentifier = "cell"
let anotherCellReuseidentifier = "anotherCell"
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(FruitTableViewCell.self, forCellReuseIdentifier: cellReuseidentifier)
tableView.register(AnotherFruitTableViewCell.self, forCellReuseIdentifier: anotherCellReuseidentifier)
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return fruitsComponents.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseidentifier, for: indexPath) as! FruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row]
cell.didEntered = {text in
self.fruitsLabels = Array(repeating: text, count: 4)
self.tableView.reloadData()
}
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: anotherCellReuseidentifier, for: indexPath) as! AnotherFruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row]
cell.fruitsTextLabel.text = fruitsLabels[indexPath.row]
return cell
}
}
}
class FruitTableViewCell: UITableViewCell, UITextFieldDelegate {
var fruitsTextField = UITextField()
let toolBarKeyBoard = UIToolbar()
let flexibleSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
var result : String!
var didEntered: ((_ text: String)->())?
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.contentView.addSubview(fruitsTextField)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
fruitsTextField.frame = CGRect(x: 250, y: 7.5, width: 100, height: 30)
fruitsTextField.backgroundColor = .yellow
fruitsTextField.textColor = UIColor(red: CGFloat(242/255.0), green: CGFloat(56/255.0), blue: CGFloat(90/255.0), alpha: 1.0)
fruitsTextField.keyboardType = .numberPad
fruitsTextField.clearButtonMode = .whileEditing
toolBarKeyBoard.sizeToFit()
fruitsTextField.inputAccessoryView = toolBarKeyBoard
let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(donePressed))
toolBarKeyBoard.setItems([flexibleSpace, doneButton], animated: false)
}
#objc func donePressed() {
fruitsTextField.endEditing(true)
didEntered?(fruitsTextField.text ?? "")
}
}
class AnotherFruitTableViewCell: UITableViewCell {
var fruitsTextLabel = UILabel()
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.contentView.addSubview(fruitsTextLabel)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
fruitsTextLabel.backgroundColor = UIColor.brown
fruitsTextLabel.frame = CGRect(x: 250.0, y: 7.5, width: 100.0, height: 30.0)
}
}

Answer 2

You can use UITextField delegate methods to achieve this in your TableViewController.
In your TableViewController cellForRowAt method:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseidentifier, for: indexPath) as! FruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row] //"I am confused why it is here"
cell.fruitsTextField.delegate = self
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: anotherCellReuseidentifier, for: indexPath) as! AnotherFruitTableViewCell
cell.textLabel?.text = fruitsComponents[indexPath.row]
return cell
}
}
Now add UITextField Delegate methods:
extension TableViewController : UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
print(textField.text!)
let cell = self.tableView.cellForRow(at: IndexPath(row: 1, section: 0)) as! AnotherFruitTableViewCell
cell.textLabel.text = textField.text!
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.endEditing(true)
return true
}
}
Hope this helps.