So I updated to Xcode 6 beta 5 today and noticed I received errors in nearly all of my subclasses of Apple's classes.
The error states:
Class 'x' does not implement its superclass's required members
Here is one example I picked because this class is currently pretty lightweight so it will be easy to post.
class InfoBar: SKSpriteNode { //Error message here
let team: Team
let healthBar: SKSpriteNode
init(team: Team, size: CGSize) {
self.team = team
if self.team == Team.TeamGood {
healthBar = SKSpriteNode(color: UIColor.greenColor(), size:size)
}
else {
healthBar = SKSpriteNode(color: UIColor.redColor(), size:size)
}
super.init(texture:nil, color: UIColor.darkGrayColor(), size: size)
self.addChild(healthBar)
}
}
So my question is, why am I receiving this error, and how can I fix it? What is it that I am not implementing? I'm calling a designated initializer.
From an Apple employee on the Developer Forums:
"A way to declare to the compiler and the built program that you really don't want to be NSCoding-compatible is to do something like this:"
required init(coder: NSCoder) {
fatalError("NSCoding not supported")
}
If you know you don't want to be NSCoding compliant, this is an option. I've taken this approach with a lot of my SpriteKit code, as I know I won't be loading it from a storyboard.
Another option you can take which works rather well is to implement the method as a convenience init, like so:
convenience required init(coder: NSCoder) {
self.init(stringParam: "", intParam: 5)
}
Note the call to an initializer in self
. This allows you to only have to use dummy values for the parameters, as opposed to all non-optional properties, while avoiding throwing a fatal error.
The third option of course is to implement the method while calling super, and initialize all of your non-optional properties. You should take this approach if the object is a view being loaded from a storyboard:
required init(coder aDecoder: NSCoder!) {
foo = "some string"
bar = 9001
super.init(coder: aDecoder)
}