How to send data back by popViewControllerAnimated for Swift?

Question

I need to send some data back from secondView to First View by popView. How can i send back the data by popViewControllerAnimated?

Thanks!

if you have small data then you can use NSUserDefaluts or NSNotificaitonCenter. — Ashok Londhe, Jun 03 '15 at 12:58
Related: http://stackoverflow.com/questions/13509832/it-possible-to-pass-data-with-popviewcontrolleranimated — Steve Melnikoff, Oct 13 '15 at 09:53
here is a TRUE way to use the delegate with popViewControllerAnimated in Swift!: http://stackoverflow.com/questions/39692791/swift-how-to-call-delegate-with-popviewcontroller — David Seek, Sep 26 '16 at 11:30

score 84 · Accepted Answer · edited Oct 24 '18 at 17:05

84

You can pass data back using delegate

Create protocol in ChildViewController
Create delegate variable in ChildViewController
Extend ChildViewController protocol in MainViewController
Give reference to ChildViewController of MainViewController when navigate
Define delegate Method in MainViewController
Then you can call delegate method from ChildViewController

Example

In ChildViewController: Write code below...

protocol ChildViewControllerDelegate
{
     func childViewControllerResponse(parameter)
}

class ChildViewController:UIViewController
{
    var delegate: ChildViewControllerDelegate?
    ....
}

In MainViewController

// extend `delegate`
class MainViewController:UIViewController,ChildViewControllerDelegate
{
    // Define Delegate Method
    func childViewControllerResponse(parameter)
    {
       .... // self.parameter = parameter
    }
}

There are two options:

A) with Segue

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
   let goNext = segue.destinationViewController as ChildViewController
   goNext.delegate = self
}

B) without Segue

let goNext = storyboard?.instantiateViewControllerWithIdentifier("childView") as ChildViewController
goNext.delegate = self
self.navigationController?.pushViewController(goNext, animated: true)

Method Call

self.delegate?.childViewControllerResponse(parameter)

edited Oct 24 '18 at 17:05

andrzej1_1

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answered Jun 03 '15 at 11:32

iDhaval

3,175
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here is a TRUE way to use the delegate with popViewControllerAnimated in Swift!: http://stackoverflow.com/questions/39692791/swift-how-to-call-delegate-with-popviewcontroller – David Seek Sep 26 '16 at 11:30
Marvellous content – Aryan Sharma Feb 09 '18 at 12:38
but iam not pushing but poping a view controller so what should i do that? – iOS Developer Aug 28 '18 at 08:00
@DavidSeek how different is solution from your question? It seems to be duplicate – andrzej1_1 Oct 24 '18 at 13:51
i dont know what went on 2 freaking years ago xD seems the same. maybe something didnt work. i dont know. seems legit answer tho – David Seek Oct 24 '18 at 15:07
Cannot find type 'parameter' in scope – Nehal Jaisalmeria Apr 14 '21 at 08:22

score 22 · Answer 2 · answered Jun 03 '15 at 11:08

22

If you want to send data by popping, you'd do something like:

func goToFirstViewController() {
  let a = self.navigationController.viewControllers[0] as A
  a.data = "data"
  self.navigationController.popToRootViewControllerAnimated(true)
}

answered Jun 03 '15 at 11:08

DHEERAJ

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If i want to popback to previousView but not first view, how can i fix it? – Varis Darasirikul Jun 03 '15 at 11:15
2

you should use delegate for this purpose – MOHAMMAD ISHAQ Jun 03 '15 at 11:18
@VarisDarasirikul `self.navigationController.popToViewController(a, animated: true)` – Zizoo Sep 27 '16 at 13:02
1

@VarisDarasirikul set the index to the view controller you want. In my case it was 1 not 0. let a = self.navigationController?.viewControllers[1] as! YourPreviousViewController. Awesome answer BTW :) – Jeff Apr 20 '17 at 22:27
Definitely an awesome answer. Learn something new every day, it’s very clever, thanks! – Lance Samaria Oct 11 '18 at 02:22
This approach prohibits the re-usability of that view controller, I think delegates are preferable. – Bruno Bieri Feb 27 '20 at 14:18

itsji10dra · Answer 3 · 2019-06-14T07:51:24.527

Extending Dheeraj's answer in case your ViewController is not first VC in the stack, here is the solution:

func popViewController() {
  guard let myVC = self.navigationController?.viewControllers.first({ $0 is MyViewController }) else { return } 
  myVC.data = "data"
  self.navigationController?.popViewController(animated: true)
}

However, this solution will break if you have 2 or more than 2 MyViewController in the stack. So, use wisely.

score 0 · Answer 4 · answered Oct 03 '18 at 06:04

Answer given here is a little complex, quite simple to just use UINavigationControllerDelegate

class FirstNavigationController: UIViewController {
    var value: String?
}

class SecondNavigationController: UIViewController, UINavigationControllerDelegate {

    func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
        guard let vc = navigationController.topViewController as? FirstNavigationController else { return }
        vc.value = "Hello again"
    }
}

score 0 · Answer 5 · answered May 22 '22 at 21:31

0

self.navigationController?.popViewController(animated: true)
        let vc = self.navigationController?.viewControllers.last as! MainViewController
        vc.textfield.text = "test"

this popviewcontroller solutions

answered May 22 '22 at 21:31

ayhnhakn

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3
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How to send data back by popViewControllerAnimated for Swift?

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