IOS 7 Swift

ios7.swift

    func paymentAuthorizationViewController(
        controller: PKPaymentAuthorizationViewController,
        didAuthorizePayment payment: PKPayment,
        completion: ((PKPaymentAuthorizationStatus) -> Void)) {
            
            self.handlePaymentAuthorizationWithPayment(payment, completion:completion);
    }

    func handlePaymentAuthorizationWithPayment(payment: PKPayment, completion: ((PKPaymentAuthorizationStatus) -> Void)!) {
        STPAPIClient.sharedClient().createTokenWithPayment(
            payment,
            completion: { (token: STPToken?, error: NSError?) in
                if ((error) != nil) {
                    completion(PKPaymentAuthorizationStatus.Failure)
                }
                self.createBackendChargeWithToken(token!, completion: completion)
            })
    }