Swift - How to forbid an initializer?
ios, swift, uiviewcontroller, xcode
Solution
- If the goal to forbid usage of all designated initializers besides yours then there's no language feature at this moment. This applies to all kinds of methods.
Overriding method must be accessible as it's enclosing type
- If the goal is to avoid empty override of `init(coder:)` each time you adding custom initialiser then think about `convenience` keyword. Swift's safety paradigm assumes that class either adds 'additional' init or has to modify behaviour of all required initialisers.
"Automatic Initializer Inheritance"
Problem
Consider the following controller class with a delegate: ``` @objc protocol FooControllerDelegate { } @objc class FooController: UIViewController { var delegate: FooControllerDelegate init(delegate: FooControllerDelegate) { self.delegate = delegate super.init(nibName: nil, bundle: nil) } // TODO: How do we forbid this init? required init(coder aDecoder: NSCoder) { // TODO: Fails to compile. super.init(coder: aDecoder) } } ``` Is there any way to forbid the usage of the `-initWithCoder:` equivalent, without making the delegate implicitly unwrapped, and placing an `assert(false)` inside the method? Ideally, it won't be necessary to write the `init(coder:)` with each subclass at all, and have it implicitly forbidden.