Swift - Objective-C load class method?

Question

In Objective-C, NSObject had a class method called load that gets called when the class is loaded for the first time. What is the equivalent in Swi

Answer 1

For Swift 2 or 3 (i.e. post-Swift 1.2), you can use:

class MySwiftClass: NSObject {
    internal override class func initialize() {
        DoStuff()
        super.initialize()
    }
}

But, as you can see, your class needs to inherit (directly or indirectly) form NSObject. This is required because the initialize() is called by the ObjC runtime.

And the initialize() method will only be called when MySwiftClass is referenced. So it will not be as magic as load().

But it will also be safer. For example: including a framework (let's say, by just adding it to your Podfile) won't allow the framework to mysteriously start to behave as soon as your app launches, without the need to add a single line of code to your project (at least… I hope!