sprite kit : contact not working - ios

Question

I am trying to make one simple game and this problem happen first my paddle can touch the ball but now it cant do that and
this code also should give me message or in simulator but it is not showing any idea?
import SpriteKit
class GameScene: SKScene , SKPhysicsContactDelegate{
var istouchingpaddle = false
let ballcatagery:UInt32 = 0 * 1 << 0
let paddlecategary :UInt32 = 0 * 1 << 1
override func didMoveToView(view: SKView) {
/* Setup your scene here */
let border = SKPhysicsBody(edgeLoopFromRect: self.frame)
border.friction = 0
self.physicsBody = border
self.physicsWorld.gravity = CGVectorMake(0,-9.8)
self.physicsWorld.contactDelegate = self
let ball = childNodeWithName ("ball") as SKSpriteNode
ball.physicsBody?.applyImpulse(CGVectorMake(30, -30))
ball.physicsBody?.allowsRotation = false
ball.physicsBody?.restitution = 1
ball.physicsBody?.linearDamping = 0
ball.physicsBody?.angularDamping = 0
ball.physicsBody!.categoryBitMask = ballcatagery
let paddle = childNodeWithName("paddle") as SKSpriteNode
paddle.physicsBody!.categoryBitMask = paddlecategary
ball.physicsBody?.contactTestBitMask = paddlecategary
}
func didBeginContact(contact: SKPhysicsContact) {
if contact.bodyA.categoryBitMask == ballcatagery && contact.bodyB.categoryBitMask == paddlecategary{
println("working ")
}
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
/* Called when a touch begins */
var touch = touches.anyObject() as UITouch
var location = touch.locationInNode(self)
if let body = self.physicsWorld.bodyAtPoint(location){
if body.node!.name == "paddle" {
istouchingpaddle = true
}
}
}
override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
if istouchingpaddle{
var touch = touches.anyObject() as UITouch
var location = touch.locationInNode(self)
var prevlocation = touch.previousLocationInNode(self)
var paddle = childNodeWithName("paddle") as SKSpriteNode
var position = paddle.position.x + (location.x - prevlocation.x)
position = max(position,paddle.size.width/2)
position = min(position, size.width - paddle.size.width/2)
paddle.position = CGPoint(x: position, y: paddle.position.y)
}
}
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
istouchingpaddle = false
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
} }

Answer 1

I can produce good results with your code if I change the way of defining categories. Try setting categories like this :
let ballcatagery: UInt32 = 0x1 << 0 // Not that you have misspelled word "category", which can lead to errors if you expect somewhere a word "category" instead of your actual "categary".
let paddlecategary : UInt32 = 0x1 << 1
I can post you the whole code , but you should be good with this.