Get value from Modal View in Swift iOS - ios

Question

i'm trying to start writing Swift and i'm trying to get a value from a modal view controller with no luck.
I have two controllers, the ViewController and modalViewController.
In ViewController i have a UITableView and with a press of a button i open the modalViewController.
Then from a UITextField i pass the value.
I have implement a protocol with delegate and func but somewhere i'm missing something or had it wrong.
ViewController.swift
import UIKit
class ViewController: UIViewController,UITableViewDelegate,modalViewControllerDelegate{
#IBOutlet var table: UITableView!
var tableData = ["First Row","Second Row","Third Row"]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func viewDidAppear(animated: Bool) {
table.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func tableView(table:UITableView?,numberOfRowsInSection section: Int) -> Int
{
return tableData.count
}
func tableView(table:UITableView?,cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell!
{
let cell:UITableViewCell = UITableViewCell(style:UITableViewCellStyle.Default,reuseIdentifier:"cell")
cell.textLabel?.text = tableData[indexPath.row]
return cell
}
func sendText(text: NSString) {
tableData.append(text)
} }
modalViewController.swift
import UIKit
protocol modalViewControllerDelegate {
func sendText(var text: NSString)
}
class modalViewController: UIViewController{
let delegate: modalViewControllerDelegate?
#IBOutlet var textField: UITextField?
#IBAction func cancelButton(sender: AnyObject) {
dismissViewControllerAnimated(true, completion: nil)
}
#IBAction func saveButton(sender: AnyObject) {
delegate?.sendText(self.textField!.text)
dismissViewControllerAnimated(true, completion: nil)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
}
}
I have no errors in the code, the delegate is not working, it's always nil.
Thanks.

Answer 1

You have to assign the delegate in your first view controller.
Also, you have to change let delegate: modalViewControllerDelegate? to a var, or else you can't change it.
Right now your delegate is empty.
It's unclear how you're accessing ModalViewController. If you're using segues:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "modalViewControllerSegue" {
var destination = segue.destinationViewController as CategoryViewController
destination.delegate = self
}
}
Or if you're doing it programmatically:
var modalViewController = ModalViewController(parameters)
modalViewController.delegate = self
presentViewController(modalViewController, animated: true, completion: nil)
Storyboard identifier:
let destination = UIStoryboard.mainStoryboard().instantiateViewControllerWithIdentifier("ModalViewController") as ModalViewController
delegate = self
showViewController(destination, sender: nil)
EDIT:
If you want to access ModalViewController by selecting a cell you need the tableView: didSelectRowAtIndexPath method:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("modalViewControllerSegue", sender: self)
}
Using this, you'll need the method prepareForSegue to set the delegate.

Answer 2

You have to set your modalViewController's delegate property before presenting it. If you're using segues, you can do this in prepareForSegue(_:).
Also, class names should begin with uppercase letters (modalViewController should be ModalViewController). Only instances should begin with lowercase letters.

Answer 3

Another option, instead of using delegation, is to use an unwind segue. Here's a tutorial: http://www.cocoanetics.com/2014/04/unwinding/
In your case, in your presenting view controller you could have the method:
func returnFromModalView(segue: UIStoryboardSegue) {
// This is called when returning from the modal view controller.
if let modalVC = segue.sourceViewController as? ModalViewController
where segue.identifier == "mySegueID" {
let text = modalVC.textField.text
// Now do stuff with the text.
}
}
And then just link up everything in the Interface Builder as shown in the tutorial.