Why is init(coder:) being called when I provide an init() function - swift

Question

I am using SpriteKit and I am loading a SceneKit file that contains a number of sprites with custom classes. The scene never actually loads though because it reaches the first custom class and throws the fatalerror from the required init?(coder:) initializer. The custom class implements an initializer though and I am having trouble pinning down why it is choosing that initializer over the one I provided.
Custom Class:
class Bat: SKSpriteNode, GameSprite {
var initialSize: CGSize = CGSize(width: 44, height: 24)
var textureAtlas: SKTextureAtlas = SKTextureAtlas(named: "Enemies")
var flyAnimation = SKAction()
init() {
super.init(texture: nil, color: .clear, size: initialSize)
self.physicsBody = SKPhysicsBody(circleOfRadius: size.width / 2)
self.physicsBody?.affectedByGravity = false
createAnimations()
self.run(flyAnimation)
}
required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") }
func createAnimations() {
let flyFrames: [SKTexture] = [textureAtlas.textureNamed("bat"),
textureAtlas.textureNamed("bat-fly")]
let flyAction = SKAction.animate(with: flyFrames, timePerFrame: 0.12)
flyAnimation = SKAction.repeatForever(flyAction)
}
func onTap() {}
}
And here is the code attempting to load the scene and then loop through the children and initialize them:
Encounter Manager:
class EncounterManager {
// Store encounter file names
let encounterNames: [String] = [
"EncounterA"
]
// Each encounter is a node, store an array
var encounters: [SKNode] = []
init() {
// Loop through each encounter scene and create a node for the encounter
for encounterFileName in encounterNames {
let encounterNode = SKNode()
// Load the scene file into a SKScene instance and loop through the children
if let encounterScene = SKScene(fileNamed: encounterFileName) {
for child in encounterScene.children {
// Create a copy of the scene's child node to add to our encounter node
// Copy the position, name, and then add to the encounter
let copyOfNode = type(of: child).init()
copyOfNode.position = child.position
copyOfNode.name = child.name
encounterNode.addChild(copyOfNode)
}
}
// Add the populated encounter node to the array
encounters.append(encounterNode)
}
}
// This function will be called from the GameScene to add all the encounter nodes to the world node
func addEncountersToScene(gameScene: SKNode) {
var encounterPosY = 1000
for encounterNode in encounters {
// Spawn the encounters behind the action, with increasing height so they do not collide
encounterNode.position = CGPoint(x: -2000, y: encounterPosY)
gameScene.addChild(encounterNode)
// Double Y pos for next encounter
encounterPosY *= 2
}
}
}
What I have noticed using breakpoints though is that it never gets past loading the scene. It fails on the line if let encounterScene = SKScene(fileNamed: encounterFileName) and the error is the fatal error in the initializer from the Bat class.
Any help understanding why it picks one initializer over the other would be greatly appreciated!

Answer 1

You are doing:
if let encounterScene = SKScene(fileNamed: encounterFileName)
Which calls SKScene's init(fileNamed:) which loads a file and decodes it with SKScene's coder init. That init loads the file and decodes each element in it with the node's coder init.
If you want to load from a file, you need to implement the coder init.