How to add a button with click event on UITableViewCell in Swift? - ios

Question

In my main page, I created a xib file for UITableViewCell. I'm loading the cell from that xib file and its working fine.
Inside of the cell I have some labels and buttons. I'm aiming to change the label by clicking to the button on the cell.
My Code likes below
import UIKit
class SepetCell: UITableViewCell{
#IBOutlet var barcode: UILabel!
#IBOutlet var name: UILabel!
#IBOutlet var fav: UIButton!
#IBOutlet var strep: UIStepper!
#IBOutlet var times: UILabel!
#IBAction func favoriteClicked(sender: UIButton) {
println(sender.tag)
println(times.text)
SepetViewController().favorite(sender.tag)
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
This is my xib files behind codes as .swift.
The codes in the main page likes below:
import UIKit
import CoreData
class SepetViewController: UIViewController, UITextFieldDelegate, UITableViewDataSource, UITableViewDelegate {
#
IBOutlet
var sepetTable: UITableView!
var barcodes: [CART] = []
let managedObjectContext = (UIApplication.sharedApplication().delegate as!AppDelegate).managedObjectContext
override func viewWillAppear(animated: Bool) {
if let moc = self.managedObjectContext {
var nib = UINib(nibName: "SepetTableCell", bundle: nil)
self.sepetTable.registerNib(nib, forCellReuseIdentifier: "productCell")
}
fetchLog()
sepetTable.reloadData()
}
func fetchLog() {
if let moc = self.managedObjectContext {
barcodes = CART.getElements(moc);
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) - > Int {
return self.barcodes.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) - > UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("productCell") as ? SepetCell
if cell == nil {
println("cell nil")
}
let product: CART
product = barcodes[indexPath.row]
cell!.barcode ? .text = product.barcode
cell!.name ? .text = product.name
cell!.fav.tag = indexPath.row
return cell!
}
func favorite(tag: Int) {
}
}
When i clicked fav button inside of the Cell. I wanted to change times label text to anything for example.
When I clicked to the fav button, the event will gone to the SepetCell.swift favoriteClicked(sender: UIButton) function.
So if i try to call:
SepetViewController().favorite(sender.tag)
It will go inside of the
func favorite(tag: Int) {
sepetTable.reloadData()
}
but sepetTable is nil when it is gone there. I think it is because of when I call this SepetViewController().favorite(sender.tag) function. It firstly creates SepetViewController class. So because of object is not setted it is getting null.
How can I reach that sepetTable or what is the best way to solve this issue.
Thanks.

Answer 1

Popular patterns for solving this problem are closures and delegates.
If you want to use closures, you would do something like this:
final class MyCell: UITableViewCell {
var actionBlock: (() -> Void)? = nil
then
#IBAction func didTapButton(sender: UIButton) {
actionBlock?()
}
then in your tableview delegate:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) - > UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("MyCellIdentifier") as? MyCell
cell?.actionBlock = {
//Do whatever you want to do when the button is tapped here
}
A popular alternative is to use the delegate pattern:
protocol MyCellDelegate: class {
func didTapButtonInCell(_ cell: MyCell)
}
final class MyCell: UITableViewCell {
weak var delegate: MyCellDelegate?
then
#IBAction func didTapButton(sender: UIButton) {
delegate?.didTapButtonInCell(self)
}
..
Now in your view controller:
then in your tableview delegate:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) - > UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("MyCellIdentifier") as? MyCell
cell?.delegate = self
And add conformance to the protocol like this:
extension MyViewController: MyCellDelegate {
didTapButtonInCell(_ cell: MyCell) {
//Do whatever you want to do when the button is tapped here
}
}
Hope this helps!

Answer 2

All patterns above are fine.
my two cents, in case You add by code (for example multiple different cells and so on..)
there is a FAR simple solution.
As buttons allow to specify a "target" You can pass directly the controller AND action to cell/button when setting it.
In controller:
let selector = #selector(self.myBtnAction)
setupCellWith(target: self, selector: selector)
...
in custom cell with button:
final func setupCellWith(target: Any? selector: Selector){
btn.addTarget(target,
action: selector,
for: .touchUpInside)
}

Answer 3

Add target for that button.
button.addTarget(self, action: #selector(connected(sender:)), for: .touchUpInside)
Set tag of that button since you are using it.
button.tag = indexPath.row
Achieve this by subclassing UITableViewCell. button on that cell, connect it via outlet.
To get the tag in the connected function:
#objc func connected(sender: UIButton){
let buttonTag = sender.tag
}

Answer 4

2 am answer: You're over thinking this. Create a custom TableViewCell class; set the prototype cell class to your new custom class; and then create an IBAction.