how to access entity from code - gameplay kit

Question

I have a node I added in the scene. Also in the scene I give it a component to bounce. The component looks like this:

class BounceComponent: GKComponent, ComponentSetupProt {

var bounce: SKAction?
var node: SKSpriteNode?

@GKInspectable var diff: CGFloat = 0.2
@GKInspectable var startScale: CGFloat = 1
@GKInspectable var duration: TimeInterval = 0.5

override init() {
    super.init()
    comps.append(self)
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

func setup() {
    print("setup")
    node = entity?.component(ofType: GKSKNodeComponent.self)!.node as? SKSpriteNode
    setupBounce()
}

func setupBounce() {
    ...
}

func performBounce() {
    print("performing")
    node?.run(bounce!)
}
}//

In the didMove function on my scene file, it calls the components setup(). This works fine. I'm trying to call the function performBounce() when I click on the button...

    if (play?.contains(pos))! {
        print("test")
        if let _ = play?.entity {
            print("we have an entity")
        }
        play?.entity?.component(ofType: BounceComponent.self)?.performBounce()
    }

When I click, the only thing it prints is "test" and the entity is nil. I was under the assumption that when you add a node to the editor, it also sets up the entity for that node, so I'm not sure why it is nil. Curious if anyone could shed some light on this?

Thanks for any help!

Play is a button I added in the scene editor and I added the component in the editor. This if statement is within my touchdown function. There is no subclass for the button, play is just a variable I store a reference to the button in the scene — Discoveringmypath, Sep 30 '17 at 12:30
is this in the code you sent me earlier? I need to see more because it can get a little tricky — Knight0fDragon, Sep 30 '17 at 12:32

score 3 · Accepted Answer · answered Sep 30 '17 at 15:14

The entity on the SKSpriteNode is a weak reference, you need to make sure you retain your entities from your gameplaykit object

class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Load 'GameScene.sks' as a GKScene. This provides gameplay related content
        // including entities and graphs.
        if let scene = GKScene(fileNamed: "Main") {

            // Get the SKScene from the loaded GKScene
            if let sceneNode = scene.rootNode as? Main {

                sceneNode.entities = scene.entities // add this

                // Set the scale mode to scale to fit the window
                sceneNode.scaleMode = .aspectFill

                // Present the scene
                if let view = self.view as! SKView? {
                    view.presentScene(sceneNode)
                    view.showsDrawCount = true
                    view.ignoresSiblingOrder = true
                    view.showsFPS = true
                    view.showsNodeCount = true
                }
            }
        }
    }



class Main: Base {
    var entities = [GKEntity]() // add this

damn, so that was important... I deleted that thinking I didn't need it. — Discoveringmypath, Sep 30 '17 at 15:29

how to access entity from code - gameplay kit

1 Answers1