Changing the State of a Button from Another Class - ios

Question

This is my goal: When the Start button is tapped, I want the Send buttons to be enabled. The following is what my view controller looks like when loaded:
As you can see, the Send buttons are disabled, which is desired. And I've disabled it by writing the following code in my TaskListTableViewCell.swift (I deleted some other irrelevant code for the sake of being succinct):
class TaskListTableViewCell: UITableViewCell {
#IBOutlet weak var sendButton: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
sendButton.enabled = false
}
}
And just in case it might help you see better, this is how the view controller looks like in the Main.storyboard:
And in my TaskListViewController, I have the following code:
#IBAction func startButtonTapped(sender: AnyObject) {
//write the code here to change sendButton.enabled = true
}
The problem is, I cannot seem to find a way to change the sendButton.enabled = true. I've tried:
#IBAction func startButtonTapped(sender: AnyObject) {
let taskListViewController = TaskListViewController()
taskListTableViewCell.sendButton.enabled = true
}
I've also tried:
class TaskListTableViewCell: UITableViewCell {
#IBOutlet weak var sendButton: UIButton!
func changeSendButtonEnabled() {
sendButton.enabled = true
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
sendButton.enabled = false
}
}
And in my TaskListViewController.swift, I wrote:
#IBAction func startButtonTapped(sender: AnyObject) {
let taskListViewController = TaskListViewController()
taskListTableViewCell.changeSendButtonEnabled()
}
But both of these solutions give this error: fatal error: unexpectedly found nil while unwrapping an Optional value.
I've read some other posts about accessing an IBOutlet from another class such as this post: How to access an IBOutlet from another class, Accessing IBOutlet from another class, Access an IBOutlet from another class in Swift, and using IBOutlet from another class in swift. However, none of these posts were able to solve my problem.

Answer 1

Please try this , It may solve your problem.
//CustomCell.swift
import UIKit
import Foundation
class CustomCell: UITableViewCell {
#IBOutlet weak var btnTap : UIButton!
#IBOutlet weak var lblTitle : UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
btnTap.enabled = false
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
//ViewController.swift
import UIKit
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate{
#IBOutlet weak var table: UITableView!
#IBOutlet weak var btnSTART: UIButton!
var isStartBtnTapped : Bool = false
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func startBtnTapped(sender: AnyObject) {
isStartBtnTapped = true
self.table.reloadData()
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1;
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3;
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let reuseIdentifier:String="cell";
var cell:CustomCell!
cell=tableView.dequeueReusableCellWithIdentifier(reuseIdentifier) as! CustomCell;
if cell==nil
{
cell=CustomCell(style: UITableViewCellStyle.Default, reuseIdentifier: reuseIdentifier);
}
if(isStartBtnTapped == true){
cell.lblTitle.text = "Enabled"
cell.btnTap.enabled = true
}else{
cell.lblTitle.text = "Disabled"
cell.btnTap.enabled = false
}
return cell;
}
}

Answer 2

Your tableview that contains tableview cells needs a data source in order to fill it with data. The data in this case being if the buttons are enabled or not. You can create an array of objects (or structs) that contain a Bool to tell the button to be enabled or not. Change the bool when start button is enabled and then call tableView.reloadData(). Your data source will then reload the array of objects and cellForRowAtIndexPath will then be called reconfiguring your cells.
The reason that your getting the fatal error is probably because the reference to the tableviewcell that you are trying to access is nil. When you call the method to change the button status, it finds nothing there and crashes. Although it's hard to tell exactly what's happening because there is code missing