Swift Hide Nav Bar on One Page - swift

Question

I have an app that opens to the main scene and checks for a token to see if the user is logged in. If they are all is good and it loads. If not it redirects them to a login screen, they login and then it pushes them back to the main screen.
I'm trying to hide the nav bar just on the login page which loads if there's no token. I've found many instances of code that work, like this:
self.navigationController.navigationBar.hidden = true
that hide it however they also hide the nav bar on the first instance of the main page. How can I avoid this?
EDIT: I've tried the following and still no luck! Same result of the navbar hiding on the login screen but hidden when the user is first moved to the main scene. Any other move to the main screen shows the navbar. How is this happening??
Attempt 1:
ON LOGIN PAGE
In viewDidLoad() -> self.navigationController!.navigationBar.hidden = true
ON MAIN PAGE
In viewDidLoad() -> self.navigationController!.navigationBar.hidden = false
Attempt 2
ON LOGIN PAGE
override func viewWillAppear(animated: Bool) {
self.navigationController!.navigationBarHidden = true
}
ON MAIN PAGE
override func viewWillAppear(animated: Bool) {
self.navigationController!.navigationBarHidden = false
}
Attempt 3
ON LOGIN PAGE
override func viewWillAppear(animated: Bool) {
self.navigationController!.navigationBarHidden = true
}
ON MAIN PAGE
override func viewWillDisappear(animated: Bool) {
self.navigationController!.navigationBarHidden = false
}
Could it have something to do with the way I'm moving to the main page after the user logs in?
ON LOGIN PAGE:
let secondViewController = self.storyboard!.instantiateViewControllerWithIdentifier("FriendsTableViewController") as! UITableViewController
//go to the main page
self.navigationController!.pushViewController(secondViewController, animated: true)

Answer 1

in viewWillDissapear you can set self.navigationController.navigationBar.hidden to false again.

Answer 2

Set it to hidden in viewDidAppear. I had to use something like this in my application and it worked.
Override func viewWillAppear(){ Self.navigationController.navigationBar.hidden true
}

Answer 3

Try this:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
/** remove the shadow image (border) altogether from nav bar **/
for parent in self.navigationController!.navigationBar.subviews {
for childView in parent.subviews {
if(childView is UIImageView) {
childView.removeFromSuperview()
}
}
}
}