Change value in a custom cell based on value in another cell - ios

Question

I have a table view with a custom cell build in it, the custom cell has two labels and one textfield. When the user edits the textfield then the label2 changes in the current cell. But I want that the value(Label2) in the second cell will also change based on the value in the current cell. Example: Value in the first cell is x, the Value in the second cell should be 2+x. How should I realize that? In my view controller I am using the following code:
var myString = [String]()
#IBOutlet weak var TableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
myString = ["a", "b"]
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myString.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! CalculationsTableViewCell
tableView.tableFooterView = UIView(frame: CGRectZero) //hide empty cells in UITableView
cell.Label?.text = myString[indexPath.row]
return cell
}
My TableViewCell:
#IBOutlet weak var Label: UILabel!
#IBOutlet weak var Label2: UILabel!
#IBOutlet weak var TextField: UITextField!
#IBAction func TextFieldEditingChanged(sender: AnyObject) {
var value: Double
value = NSString(string: TextField.text!).doubleValue
Label2.text = "\(value)"
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}

Answer 1

Firstly you should / could make use of the delegate pattern to communicate from the cell back to your controller:
create a protocol with a method named e.g. userEnteredNumber
let your view controller conform to that protocol
create a field in the TableViewCell called delegate - its type should the previously created protocol
when setting up the cell in cellForRowAtIndexPath assign self to the delegate property of the cell
as soon as the user enters a value call the delegate method on the previously set delegate
Secondly you have to somehow remember the state of your application. The thing with tableviews is that the iOS can decide to reload the contents of the tableView at any point (theoretically) and your controller has to keep track of the exact content each cell should have.
I do not know what the exact requirements are for your app but you should probably assign the value that gets transmitted via the protocol method to some variable in your viewController. Then you trigger a tableView reloadData and finally you have to alter the cellForRowAtIndexPath method to set the desired properties of some of the cells based on the stored value.