opening a tab bar controller on successful login swift - ios

Question

I am extremely new to swift and storyboards. I have an initial view set which presents the user with login or register options. on the success of my login web service, I am trying to open a tab bar. I am getting into the success of the webservice as I can see the response.
My code for attempting to load the tab bar is as folllows in my initial view controller:
func loadHomeScreen()
{
emailField.text = ""
passwordField.text = ""
self.presentViewController(UIStoryboard.tabbarController()!, animated: true, completion: nil)
}
And at the very bottom of that file, I have the following:
private extension UIStoryboard {
class func mainStoryboard() -> UIStoryboard { return UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) }
class func tabbarController() -> TabbarController? {
return mainStoryboard().instantiateViewControllerWithIdentifier("TabbarControllerID") as? TabbarController
}
}
And in my storyboard I have given the tabbarcontroller the id above. When I run the app (tested on the simulator for iphone6), I am getting the error 'found nil while unwrapping an Optional value' and this is pointing to the line of code in my loadHome func above (self.presentViewController(UIStoryboard.tabbarController()!, animated: true, completion: nil))
Any help would be appreciated

Answer 1

You could instead instantiate your storyboard like so and the code would look like this under loadHomeScreen():
emailField.text = ""
passwordField.text = ""
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("TabbarControllerID") as! TabbarController
self.presentViewController(vc, animated: true, completion: nil)
You may need to change the bundle to the "mainBundle" as you have in your code, but this should work.
This may not be the optimal solution if your plan is to extend UIStoryboard for instantiating your ViewControllers but I think this might be a little easier/cleaner, depending on how your project is set up.