Create an animation when changing the path of a subLayer to another path

I have a UIView and its layer in which I added a CAShapeLayer as a subLayer with a path.

When I tap on a UIButton, I change the path of the subLayer with another path.

How can I animate this?

Is it possible to have an animation as soon as the path changes?

I tried to add:

let caAnimation = CABasicAnimation()
caAnimation.keyPath = "path"
caAnimation.duration = 2

shapeLayer.addAnimation(caAnimation, forKey: "path")

in the init(coder aDecoder: NSCoder) method of my UIView in order to have an animation when the path is changed in layoutSubviews() method but it doesn't work.

What did I do wrong?