How do I manage recurrent child UIViewControllers?

Question

Scenario:

1. I instantiate a UIViewController and added it to a containerViewController.
2. I dismiss (remove) this child
3. I select this same child to display again.

My Concern: I wish to create a single child UIViewController instance.
But It appears that I would create an additional instance of the child view controller per 'case' iteration, which I do not want.

Question: Does Swift already handle this?
...or must I check for the current view controller's instance prior to making it a child?

If I have to check for its existance, then I'll have to make 'viewController' global for all cases.

Answer 1

No Swift doesn't handle this automatically. You must check the existing child view controllers to prevent adding duplicates.

You could use code like this:

if let controller = parent.childViewControllers.filter { $0 is CountriesViewController }.first {
    // use existing child controller here
}
else {
    // create new child controller and add it to parent here
}