Initialization Properties in Swift 2

Question

I am trying to build a custom UIView and am lost as far as initialization goes.

Code One

class CustomUIView: UIView {
    var propertyToInitialize: CGRect

    //Custom Initializer
    override init(frame: CGRect) {
         self.propertyToInitialize = CGRect(x: 0, y: 0, width: (superview?.frame.size.width)!, height: (superview?.frame.size.height)!)
         super.init(frame: frame)
    }
}

When I use the above code the error XCode gives me is as follows.

Error

Use of 'self' property access 'superview' before super.init initializes self

So I modified my code

Code Two

class CustomUIView: UIView {
    var propertyToInitialize: CGRect

    //Custom Initializer
    override init(frame: CGRect) {
         self.propertyToInitialize = CGRect()
         super.init(frame: frame)
         self.propertyToInitialize = CGRect(x: 0, y: 0, width: (superview?.frame.size.width)!, height: (superview?.frame.size.height)!)
    }
}

Question

Is this bad design? Should I take a different approach? Am I initializing the property twice therefore, using more memory?

Answer 1

The whole thing is bad design. Make the propertyToInitialize an Optional wrapping a CGRect, so that it doesn't need a value at initialization time, and move your code to your view's didMoveToSuperview, which is the first moment where the concept of a superview has any meaning. Even better, don't make this a property at all; the superview can be examined at anytime you need this information, so it's pointless to duplicate it in a property.