title: swift - Populate STPPaymentCardTextField Programmatically
body: <p>I'm developing an app and using Stripe SDK and Card.io SDK. What i want to happen is populate the <code>STPPaymentCardTextField</code> Card Number,Expiry Month and Year with <code>Card.io</code> scanned credit card value. I Tried:</p>
  
  <pre><code>var paymentField = STPPaymentCardTextField()
  
  func userDidProvideCreditCardInfo(cardInfo: CardIOCreditCardInfo!, inPaymentViewController paymentViewController: CardIOPaymentViewController!) {
      var scanViewController: CardIOPaymentViewController = CardIOPaymentViewController(paymentDelegate: self)
      paymentField.cardNumber = cardInfo.cardNumber
      paymentField.expirationMonth = cardInfo.expiryMonth
      paymentField.expirationYear = cardInfo.expiryYear
  
      paymentViewController.dismissViewControllerAnimated(true, completion: nil)
  }
  </code></pre>
  
  <p>I'm having an error <code>Cannot assign to the result of this expression</code> for each <code>paymentField</code> append. 
  What do you think i can do with this? Thanks!</p>