Can't pass datas back from UIView Popover Dismiss - ios

Question

I have set a "Show as popover" segue between a UIView (A) and another UIView (B) (embed in a Navigation Controller) activated on a button's clic.
i am trying to pass datas back from (B) to (A) when i dismiss it (i want to keep the popover animation on both ways).
I have tried many methods i found mostly here, on Stackoverflow, but as of now i never successfully retrieved my data on (A).
I tried Delegates and protocols as well as other simpler methods. The last in date is the following one:
In (A), i just try to print the variable that should be storing the datas in ViewWillAppear :
class SearchBarsController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate {
var testValue:String = ""
override func viewWillAppear(_ animated: Bool) {
print(testValue) // print is empty
super.viewWillAppear(animated)
}
}
In (B), i dismiss the popover and try to send the datas back on a button clic :
class SearchFilterViewController: UIViewController {
#IBAction func DismissPopoverOnClic(_ sender: Any) {
if let navController = presentingViewController as? UINavigationController {
let presenter = navController.topViewController as! SearchBarsController
presenter.testValue = "Test"
print("success") //never called
}
self.dismiss(animated: true, completion: nil)
}
}
on (B) i'd like to set up some filter that i'd use on (A) to present search results in a tableview. But actually the testValue's value is always blank.

Answer 1

oky so you can do it using unwind segue here is sample project :
sample projecct
process :
Add this method to SearchBarsController below viewWillAppear
#IBAction func unWindFromFilterViewController(_ sender: UIStoryboardSegue) {
}
Than go to Storyboard and go to SearchFilterViewController and then cntrl + Drag from DismissPopoverOnClic to top of the exit button then select unWindFromFilterViewController .
Than this the SearchFilterViewController write this method for passing data
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destVC = segue.destination as? ViewController {
destVC.testValue = "Test"
}
}
You will get your desired data back . thanks

Answer 2

When passing back data to a viewController, the most efficient way to implement it using delegate
protocol SearchFilterViewControllerDelegate {
func setTextValue(string : String)
}
class SearchFilterViewController: UIViewController {
var delegate : SearchFilterViewControllerDelegate?
#IBAction func DismissPopoverOnClic(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
delegate?.setTextValue(string : "Test Value")
}
}
class SearchBarsController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate {
var filterViewController : SearchFilterViewController?
func popup() {
// your pop up code and init filterViewController
filterViewController.delegate = self **//without this line, the delegate will be nil, no nothing will happen.**
}
}
extension SearchBarsController : SearchFilterViewControllerDelegate {
func setTextValue(string : String) {
print(string)
}
}