Separate UIViewController in same Storyboard - swift

Question

Issue
I have a single page app with a single view controller. On the screen there is a button that slides out/in a (smaller) UIView with a TableView (functions correctly). My goal is to simplify my view controller, hence my idea was to split off the UIView with the TableView into its own view controller. Therefore I've created a second view controller in the Storyboard and created a class HintsViewTableViewController, that contains the TableView datasource and delegate methods.
Main View controller
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var HintsViewTableVC = HintsViewTableViewController()
HintsViewTableViewController
class HintsViewTableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var HintsViewTableView: UITableView!
#IBOutlet var hintsLabel: UILabel!
override func viewDidLoad() {
hintsLabel.text = "HINT" <---fatal error: unexpectedly found nil while unwrapping an Optional value
}
// MARK: - Table view data source
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return 4
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return CGFloat (40)
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
// Configure the cell...
cell.textLabel!.text = "\(indexPath.row)"
return cell
}
}
Problem
If the storyboard entry point is the Main View Controller, the compiler gives an error stating that my property hintsLabel! is nil and crashes.
If I move the storyboard entry point directly to the HintsViewTableViewController, then the app runs and shows the correct view on screen.
Question
Apparently, the procedure to initialize a view controller directly (using the storyboard entry point) is different from assigning the view controller to a variable (as I do in the first case). I've searched high and low for init methods, but have come up blank.
Another solution I've tried: making a separate XIB file and linking this to my HintsViewTableViewController, however TableViews in XIB files can't have prototype cells.
What am I missing here, or stated differently: what's the correct procedure to separate a UIView into a separate view controller (in the same Storyboard)?

Answer 1

The problem is that when you instantiate your HintsViewTableViewController like this:
var HintsViewTableVC = HintsViewTableViewController()
you are creating an instance of the class, BUT that class knows nothing about your Storyboard, so all of the #IBOutlets will be nil because they aren't wired to anything.
Instead, you need to ask the Storyboard to create the ViewController:
self.storyboard?.instantiateViewControllerWithIdentifier("hintsController") as! HintsViewTableViewController
where hintsController is the Storyboard ID you have set for that ViewController in the Identity Inspector.
Note: You will need to make this call to the Storyboard in a method (such as viewDidLoad where self will refer to an instance of your ViewController class.
If you want to declare it as a property like you were doing before, making it a lazy property will allow it to be created when first accessed (and self will be available then):
lazy var hintsViewTableVC: HintsViewTableViewController = { self.storyboard?.instantiateViewControllerWithIdentifier("hintsController") as! HintsViewTableViewController }()