SKScene nodes not detecting touch - ios

Question

I am trying to make an ARKit app for ios and the nodes in the scene are not responding to touch. The scene is properly displayed but I haven't been able to detect any touch.
fileNamed: "TestScene" refers to a TestScene.sks file in my project which is empty and I add the node in the code as shown below.
let detailPlane = SCNPlane(width: xOffset, height: xOffset * 1.4)
let testScene = SKScene(fileNamed: "TestScene")
testScene?.isUserInteractionEnabled = true
let winner = TouchableNode(fontNamed: "Chalkduster")
winner.text = "You Win!"
winner.fontSize = 65
winner.fontColor = SKColor.green
winner.position = CGPoint(x: 0, y: 0)
testScene?.addChild(winner)
let material = SCNMaterial()
material.diffuse.contents = testScene
material.diffuse.contentsTransform = SCNMatrix4Translate(SCNMatrix4MakeScale(1, -1, 1), 0, 1, 0)
detailPlane.materials = [material]
let node = SCNNode(geometry: detailPlane)
rootNode.addChildNode(node)
For TouchableNode I have the following class
class TouchableNode : SKLabelNode {
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
print("Touch detected")
}
}

Answer 1

I've achieved this affect using gesture recognize
private func registerGestureRecognizers() -> Void {
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTap))
sceneView.addGestureRecognizer(tapGestureRecognizer)
}
then have a function to handle the tap gesture
#objc private func handleTap(sender: UITapGestureRecognizer) -> Void {
let sceneViewTappedOn = sender.view as! SCNView
let touchCoordinates = sender.location(in: sceneViewTappedOn)
let hitTest = sceneViewTappedOn.hitTest(touchCoordinates)
if !hitTest.isEmpty {
let hitResults = hitTest.first!
var hitNode = hitResults.node
// do something with the node that has been tapped
}
}
}

Answer 2

You need to do isUserInteractionEnabled = true first.
So, something like:
class TouchableNode : SKLabelNode {
override init() {
super.init()
isUserInteractionEnabled = true
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
isUserInteractionEnabled = true
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
print("Touch detected")
}
}