Swift - How to calculate a sum of buttons in table view cell - ios

Question

I have two types of table cells, one that has 6 buttons, and each button has a number value, and then a second cell that has a button to calculate the total sum of the selected numbers, and a label to display this total sum in.
My issue is I cannot get the label to calculate the total. Here is what I have so far
Number Cell:
protocol ToggleNumberCellDelegate: AnyObject {
/// This method detects the selected value of the cell.
func toggleNumberCell(_ toggleNumberCell: ToggleNumberCell, selectedValue: Int)
}
class ToggleNumberCell: UITableViewCell {
static let reuseIdentifier = String(describing: ToggleNumberCell.self)
#IBOutlet private weak var titleLabel: UILabel!
#IBOutlet private weak var zeroButton: UIButton!
#IBOutlet private weak var oneButton: UIButton!
#IBOutlet private weak var twoButton: UIButton!
#IBOutlet private weak var threeButton: UIButton!
#IBOutlet private weak var fourButton: UIButton!
#IBOutlet private weak var fiveButton: UIButton!
#IBOutlet private weak var sixButton: UIButton!
private weak var delegate: ToggleNumberCellDelegate?
private var value: Int?
//...
#IBAction func buttonTapped(_ sender: UIButton) {
switch sender {
case zeroButton:
self.zeroButton.backgroundColor = UIColor.NBABlue
self.zeroButton.tintColor = UIColor.white
self.value = 0
self.delegate?.toggleNumberCell(self, selectedValue: self.value!)
print("The value you tapped is \(value)")
case oneButton:
self.oneButton.backgroundColor = UIColor.NBABlue
self.oneButton.tintColor = UIColor.white
self.value = 1
self.delegate?.toggleNumberCell(self, selectedValue: self.value!)
print("The value you tapped is \(value)")
case twoButton:
self.twoButton.backgroundColor = UIColor.NBABlue
self.twoButton.tintColor = UIColor.white
self.value = 2
self.delegate?.toggleNumberCell(self, selectedValue: self.value!)
print("The value you tapped is \(value)")
The above code just sets up the buttons, and gives each a value by using its delegate.
Label Cell
class CalculateCell: UITableViewCell, ToggleNumberCellDelegate {
var increment = 0
static let reuseIdentifier = String(describing: CalculateCell.self)
#IBOutlet private weak var calculateButton: UIButton!
#IBOutlet private weak var totalLabel: UILabel!
func configure(answer: AnswerModel) {
self.backgroundColor = UIColor.secondarySystemGroupedBackground
self.totalLabel.text = answer.text
self.totalLabel.font = .preferredFont(forTextStyle: .headline)
calculateButton.layer.cornerRadius = 10.0
}
override func prepareForReuse() {
super.prepareForReuse()
self.totalLabel.text = nil
}
#IBAction func calculateTapped(_ sender: UIButton) {
// You need to get the selected value in here somehow.
}
func toggleNumberCell(_ toggleNumberCell: ToggleNumberCell, selectedValue: Int) {
increment = selectedValue
}
}
Here I called the delegate to get the selected value, but I think I did this wrong, can someone tell me how I can calculate to total value?
Here is a screenshot of what I want to achieve.

Answer 1

You have a basic problem with your approach. You should not store data in table view cells. They are views, and should display data, not store data.
You should set up a model object to store the state of your UI. (it could be as simple as an array of integers, one of the value of each ToggleNumberCell in your table view.)
You should have a controller object serve as the delegate for the ToggleNumberCell. When its toggleNumberCell method gets called, it would update the count for that cell's entry in your data model, and then tell the total cell to update itself. Your table view data source would query the model and use the value for each entry in the model to calculate the totals, then install that value in the total cell.

Answer 2

I would recommend you make the UIViewController (than manages the UITableView) the ToggleNumberCellDelegate. Then that view controller can keep track of the total of all of the buttons. The view controller then can provide the total to
the CalculateCell. This separates the logic between the cells. Ideally the controller manages the logic, while the cells are simply views displaying the data.
Also, I would change the toggleNumberCell function to the following:
func toggleNumberCell(_ toggleNumberCell: ToggleNumberCell, selectedValue: Int) {
// Using += will result in adding to the existing value instead of overwriting it
increment += selectedValue
}