How to show one of the two ViewControllers by tapping Cancel button?

Question

I`ve one ViewController to which I can hit by clicking on TabBarItem or from Table View Controller B by pressing plus on navigation bar.

My problem

How, by clicking on the Cancel button on the ViewController, I can go to Table View Controller B if I hit to ViewController from Table View Controller B by clicking plus or go to Table View Controller A if I hit to ViewController by selecting the second (blue) tab bar item?

I want set two action to Cancel button on the ViewController - depending on the previous Controller I want to go to TableViewControllerA or TableViewControllerB, is it possible?

Details

First version of the transition: By clicking Plus button on the TableViewControllerB I go to ViewController and on ViewController I click Cancel button and return to TableViewControllerB.

Second version of the transition: By clicking second TabBarItem on the TabBar Controller I go to ViewController and on ViewController I click Cancel button and return to TableViewControllerA.

Answer 1

There are two ways to achieve, what you want, according to your view controller flow diagram.

1. Pop to root view controller
2. Pop to Specific view controller (TableViewController A)

You need to decide which options should you use, according to your requirement.

Add/replace following code to your cancel button and try both options one after another:

@IBAction btnCancel_Action(button: UIButton) {

    // 1. Pop to root view controller
    self.navigationController?.popToRootViewController(animated: true)

    // OR
    // 2. Pop to Specific view controller (TableViewController A)

   if let navController = self.navigationController {

        for viewcontroller in navController.viewControllers {
            // `TableViewControllerA` class name for view controller or you can use instance of `TableViewControllerA` also with `viewcontroller == <TableViewControllerA>`

            if viewcontroller is <TableViewControllerA> { 
            //if viewcontroller == <IntanceOfTableViewControllerA> {  
               self.navigationController?.popToViewController(viewcontroller, animated: true)
                break
            }

        }
    }
}

Edited answer according to question edit: Try this

@IBAction btnCancel_Action(button: UIButton) {
 if let tabController = self.tabBarController {
            if tabController.selectedIndex == 0 {
                self.navigationController?.popViewController(animated: true)
            } else if tabController.selectedIndex == 1 {
                self.tabBarController?.selectedIndex = 0


                // If your tabbar 0 has TableViewControllerB is active on screen then use following code
                if let navController = self.tabBarController?.navigationController {
                    navController.popToRootViewController(animated: false)

                    /*
                    //or
                    DispatchQueue.main.asyncAfter(deadline: .now() + 0.5, execute: {
                        navController.popToRootViewController(animated: false)
                    })
                     */
                }


            }
        }
}