Issue Detecting Button cellForRowAt - ios

Question

I need to detect if the button has been clicked in the UITableViewController
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let LikesBtn = cell.viewWithTag(7) as! UIButton
}

Answer 1

The easiest and most efficient way in Swift is a callback closure.
Subclass UITableViewCell, the viewWithTag way to identify UI elements is outdated.
Set the class of the custom cell to the name of the subclass and set the identifier to ButtonCellIdentifier in Interface Builder.
Add a callback property.
Add an action and connect the button to the action.
class ButtonCell: UITableViewCell {
var callback : (() -> Void)?
#IBAction func buttonPressed(_ sender : UIButton) {
callback?()
}
}
In cellForRow assign the callback to the custom cell.
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ButtonCellIdentifier", for: indexPath) as! ButtonCell
cell.callback = {
print("Button pressed", indexPath)
}
return cell
}
When the button is pressed the callback is called. The index path is captured.
Edit
There is a caveat if cells can be added or removed. In this case pass the UITableViewCell instance as parameter and get the index path from there
class ButtonCell: UITableViewCell {
var callback : ((UITableViewCell) -> Void)?
#IBAction func buttonPressed(_ sender : UIButton) {
callback?(self)
}
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ButtonCellIdentifier", for: indexPath) as! ButtonCell
let item = dataSourceArray[indexPath.row]
// do something with item
cell.callback = { cell in
let actualIndexPath = tableView.indexPath(for: cell)!
print("Button pressed", actualIndexPath)
}
return cell
}
If even the section can change, well, then protocol/delegate may be more efficient.

Answer 2

First step:
Make Subclass for your custom UITableViewCell, also register protocol.
Something like this:
protocol MyTableViewCellDelegate: class {
func onButtonPressed(_ sender: UIButton, indexPath: IndexPath)
}
class MyTableViewCell: UITableViewCell {
#IBOutlet var cellButton: UIButton!
var cellIndexPath: IndexPath!
weak var delegate: MyTableViewCellDelegate!
override func awakeFromNib() {
super.awakeFromNib()
cellButton.addTarget(self, action: #selector(self.onButton(_:)), for: .touchUpInside)
}
func onButton(_ sender: UIButton) {
delegate.onButtonPressed(sender, indexPath: cellIndexPath)
}
}
In your TableViewController, make sure it conform to your just created protocol "MyTableViewCellDelegate".
Look at the code below for better understanding.
class MyTableViewController: UITableViewController, MyTableViewCellDelegate {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "cellId", for: indexPath) as? MyTableViewCell {
cell.cellIndexPath = indexPath
cell.delegate = self
return cell
} else {
print("Something wrong. Check your cell idetifier or cell subclass")
return UITableViewCell()
}
}
func onButtonPressed(_ sender: UIButton, indexPath: IndexPath) {
print("DID PRESSED BUTTON WITH TAG = \(sender.tag) AT INDEX PATH = \(indexPath)")
}
}

Answer 3

Here is what I use:
First initialize the button as an Outlet and its action on your TableViewCell
class MainViewCell: UITableViewCell {
#IBOutlet weak var testButton: UIButton!
#IBAction func testBClicked(_ sender: UIButton) {
let tag = sender.tag //with this you can get which button was clicked
}
}
Then in you Main Controller in the cellForRow function just initialize the tag of the button like this:
class MainController: UIViewController, UITableViewDelegate, UITableViewDataSource, {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! MainViewCell
cell.testButton.tag = indexPath.row
return cell
}
}