Navigation types in iOS

Navigation in normal approach :

let cdplvc = self.storyboard?.instantiateViewController(withIdentifier: "CDPLVC") 

self.navigationController?.pushViewController(cdplvc!, animated: false)

In PageViewController : 

let cdplvc = self.storyboard?.instantiateViewController(withIdentifier: "CDPLVC") 

//We need to fix it navigation

(UIApplication.shared.keyWindow?.rootViewController as? UINavigationController)?.pushViewController(csvc!, animated: true)

Ex. PageViewController : https://stackoverflow.com/questions/56801714/in-pageviewcontroller-navigation-not-working

Set navigation bar back button :

 In pageViewController :

let csvc = self.storyboard?.instantiateViewController(withIdentifier: "CSVC")

let backButton = UIBarButtonItem()

//backItem.title = "Login"

backButton.barButtonTitle(titleString:"Status”)//Through extension class

(UIApplication.shared.keyWindow?.rootViewController as? UINavigationController)?.self.navigationBar.topItem?.backBarButtonItem = backButton

(UIApplication.shared.keyWindow?.rootViewController as? UINavigationController)?.pushViewController(csvc!, animated: true)

extension UIBarButtonItem {

    func barButtonTitle(titleString:String) { 

        title = titleString

        if UIDevice.current.userInterfaceIdiom == .pad {

            setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Medium", size: 20)!], for: UIControl.State.normal);

        } else {

            setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Medium", size: 15)!], for: UIControl.State.normal);

        }        

    }

}

In Normal approach :

let cdplvc = self.storyboard?.instantiateViewController(withIdentifier: "CDPLVC") 

        

let backItem = UIBarButtonItem()

backItem.title = "Login"

self.navigationItem.backBarButtonItem = backItem

//If required font size etc…

if UIDevice.current.userInterfaceIdiom == .pad {

     backItem.setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Medium", size: 20)!], for: UIControl.State.normal);

} else {

     backItem.setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Medium", size: 15)!], for: UIControl.State.normal);

}

        

self.navigationController?.pushViewController(cdplvc!, animated: false)