Respond to a UITableCell action in the UIViewController

Question

So I have a UITableViewCell:

Here is the code:

import Foundation
import UIKit

class Cell_Switch: UITableViewCell{

    @IBOutlet weak var label: UILabel!
    @IBOutlet weak var select: UISwitch!
    override func awakeFromNib() {
        super.awakeFromNib()
    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }

    override var layoutMargins: UIEdgeInsets {
        get { return UIEdgeInsetsZero }
        set(newVal) {}
    }
    @IBAction func onSwitch(sender: AnyObject) {
        //I don't want to respond here!!!
    }
}

And here's the UITableView code:

import Foundation
import UIKit

class PreferencesInterestedDays: UIViewController,UITableViewDataSource,UITableViewDelegate{
    @IBOutlet weak var table: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        var nib = UINib(nibName: "Cell_Switch", bundle: nil)
        table.registerNib(nib, forCellReuseIdentifier: "Cell_Switch")
        table.separatorInset = UIEdgeInsetsZero

    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }





    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        var cell:Cell_Switch = self.table.dequeueReusableCellWithIdentifier("Cell_Switch") as Cell_Switch

        //what do I do here???
        //not working: cell.select.actionsForTarget(self, forControlEvent: UIControlEvents.ValueChanged)



        return cell
    }
    //this event doesn't fire!
    @IBAction func onSwitch(sender: AnyObject) {
        //doesn't work... ;(
        println("Hello!")
    }



    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        table.deselectRowAtIndexPath(indexPath, animated: false)
    }
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 7
    }
    func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        return 44.0
    }
}

Here's what it looks like:

Each switch selected has a different response. I need to handle the actions (and get the row number) in the UITableView class, not in the UITableViewCell class...

What to do?

XCode 6.2, iOS 8.2

Answer 1

You should delegate from Cell your action and send itself in delegate method. Like TableView does it with your view controller through dataSource and Delegate.

This article would be useful for you - https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Protocols.html

Answer 2

Simple solution would be

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        var cell:Cell_Switch = self.table.dequeueReusableCellWithIdentifier("Cell_Switch") as Cell_Switch

        cell.select.addTarget(self, action: Selector("onSwitch:"), forControlEvents: UIControlEvents.ValueChanged)

        return cell
    }

    @IBAction func onSwitch(sender: AnyObject) {
        println("Hello!")
    }

Note, remove any reference of IBAction inside Cell_Switch.

Cheers.

Answer 3

Add target on each switch manually in your cellForRowAtIndexPath

cell.select.addTarget(self, action:"onSwitch:", forControlEvent: .ValueChanged)

Then

func onSwitch(sender: UISwitch){
    //do stuff
}

Answer 4

Other responses explain how to add action method. So I am going to explain how you should implement that action method.

func onSwitch(sender: UISwitch) {
    let point = tableView.convertPoint(CGPoint.zeroPoint, fromView: sender)
    if let indexPath = tableView.indexPathForRowAtPoint(point) {
        // Now you have indexPath. You now know which UISwitch sends that action.
    }
}