Increment Label Value with UIStepper in UITableViewCell - ios

Question

I want to be able to use a UIStepper that is located in each tableview row. I would like each UIStepper to update a label in the same tableview row that the UIStepper is in.
The code that I am trying is as follows
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cartListCell = tableView.dequeueReusableCell(withIdentifier: reuseCartListingCellIdentifier, for: indexPath) as? CartListingItemTableViewCell
cartListCell?.UI_STEPPER_NAME.value = VALUE_FROM_ARRAY
return cartListCell!
}
#IBAction func CartStoreQtyStepperAction(_ sender: UIStepper) {
// I need to update the value of a label in the tableview cell that tapped
}
UPDATED IMPLEMENTATION
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
cartListCell?.CartListingProductQtyStepperOutlet.tag = indexPath.row
cartListCell?.CartListingProductQtyStepperOutlet.addTarget(self, action: #selector(self.CartStoreQtyStepperAction(_:)), for: UIControlEvents.valueChanged)
cartListCell?.tag = Int(CartStoreItemIdArray [indexPath.row])!
return cartListCell!
}
#IBAction func CartStoreQtyStepperAction(_ sender: UIStepper)
{
let stepperValue = Int(sender.value)
let indexPath = IndexPath(row: stepperValue, section: 0)
print(stepperValue)
if let cell = yourTableView.cellForRow(at: indexPath) as? CartListingItemTableViewCell
{
print(cell?.tag)
}
}
I am not able to access the tableview cell and the label in that when I am doing it like this. Can someone guide me how to do this?

Answer 1

// Custom tableview cell code
class CartListingItemTableViewCell: UITableViewCell {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var stepper: UIStepper!
}
// your view controller code (tableview data source)
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cartListCell = tableView.dequeueReusableCell(withIdentifier: reuseCartListingCellIdentifier, for: indexPath) as? CartListingItemTableViewCell
let stepperValue = yourArray[indexPath.row]
cartListCell?.label.text = String(stepperValue) ?? "0"
cartListCell?.stepper.value = Int(stepperValue) ?? 0
cartListCell?.stepper.tag = indexPath.row
cartListCell?.stepper.addTarget(self, action: #selector(self.stepperValueChanged(_:)), for: UIControlEvents.valueChanged)
return cartListCell!
}
// handle stepper value change action
#IBAction func stepperValueChanged(_ stepper: UIStepper) {
let stepperValue = Int(stepper.value)
print(stepperValue) // prints value
let indexPath = IndexPath(row: stepperValue, section: 0)
if let cell = yourTableView.cellForRow(at: indexPath) as? CartListingItemTableViewCell {
cell.label.text = String(stepperValue)
yourValueArray[index] = stepperValue
}
}

Answer 2

This is a solution for Swift 4 using NSKeyValueObservation
First of all you need a property in your data model to keep the current value of the stepper.
var counter = 0.0
In the custom cell create outlets for the stepper and the label and a property for the observation. Connect the outlets.
#IBOutlet weak var stepper : UIStepper!
#IBOutlet weak var label : UILabel!
var observation : NSKeyValueObservation?
In the controller in cellForRow add the observer, dataSourceArray is the data source array.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cartListCell = tableView.dequeueReusableCell(withIdentifier: reuseCartListingCellIdentifier, for: indexPath) as! CartListingItemTableViewCell
let item = dataSourceArray[indexPath.row]
cartListCell.stepper.value = item.counter
cartListCell.label.text = "\(item.counter)"
cartListCell.observation = cell.stepper.observe(\.value, options: [.new]) { (_, change) in
cartListCell.label.text = "\(change.newValue!)"
item.counter = change.newValue!
}
return cartListCell
}

Answer 3

Solution for Swift 4 swift4.
Add these lines in cellforRowAt.
cartListCell.UI_STEPPER_NAME.tag = indexPath.row
cartListCell.UI_STEPPER_NAME.addTarget(self, action: #selector(CartStoreQtyStepperAction), for: .touchUpInside)
To access cell items in the stepper function use this line.
let cartListCell = sender.superview?.superview as! CartListingItemTableViewCell
//check whether your superview is table cell.
//then use the cell instance to update the cell label
Use sender.tag in the function to access particular cell for example.
cartListCell.UI_STEPPER_NAME.text = "\(VALUE_FROM_ARRAY[sender.tag])"
//sender.tag is similar to indexPath.row as we pass the tag value in the cellforRowAt.
//It will work then please accept my answer👍🏼😄.

Answer 4

Assign tag value to sender of UIStepper in cellForRowAt and access the change of UIStepper value in CartStoreQtyStepperAction action using same tag.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cartListCell = tableView.dequeueReusableCell(withIdentifier: reuseCartListingCellIdentifier, for: indexPath) as? CartListingItemTableViewCell
//Assign tag value
cartListCell?.UI_STEPPER_NAME.tag = indexPath.row
cartListCell?.UI_STEPPER_NAME.value = VALUE_FROM_ARRAY
cartListCell?.stepper.addTarget(self, action: #selector(self.CartStoreQtyStepperAction(_:)), for: UIControlEvents.valueChanged)
return cartListCell!
}
#IBAction func CartStoreQtyStepperAction(_ sender: UIStepper) {
let index = sender.tag
yourValueArray[index] = sender.value
//Reload particular cell for tableView
}