Issue #6 support createCard() as a request.

No documentation yet, and we may need to restrict this to just
credit and debit card payment types, but it's working to try out.

src/Gateway.php

@@ -287,6 +287,11 @@ public function getCard(array $parameters = [])
         return $this->createRequest(Message\GetCardRequest::class, $parameters);
     }
 
+    public function createCard(array $parameters = [])
+    {
+        return $this->createRequest(Message\CreateCardRequest::class, $parameters);
+    }
+
     /**
      * @param  array $parameters
      * @return Message\GetBankStatusRequest

src/Message/AbstractResponse.php

@@ -8,6 +8,8 @@
 
 use Omnipay\Common\Message\RedirectResponseInterface;
 use Omnipay\Common\Message\AbstractResponse as OmnipayAbstractResponse;
+use Omnipay\GiroCheckout\Gateway;
+use Omnipay\Omnipay;
 
 abstract class AbstractResponse extends OmnipayAbstractResponse
 {
@@ -23,4 +25,39 @@ protected function getDataItem($name, $default = null)
         $data = $this->getData();
         return isset($this->data[$name]) ? $this->data[$name] : $default;
     }
+
+    /**
+     * Get the card reference, if one was requested.
+     * We don't know what was originally requeste, so we just go to
+     * the gateway to ask for a reference.
+     */
+    public function getCardReference()
+    {
+        if (! $this->isSuccessful()) {
+            // The transaction was not successful, so there won't be a
+            // card reference to fetch.
+
+            return null;
+        }
+
+        // Build a new request.
+
+        $gateway = Omnipay::create('\\' . Gateway::class);
+
+        $gateway->setMerchantId($this->request->getMerchantId(true));
+        $gateway->setProjectId($this->request->getProjectId(true));
+        $gateway->setProjectId($this->request->getProjectId(true));
+        $gateway->setProjectPassphrase($this->request->getProjectPassphrase());
+        $gateway->setPaymentType($this->request->getPaymentType());
+
+        $request = $gateway->getCard();
+
+        $request->setTransactionReference($this->getTransactionReference());
+
+        $response = $request->send();
+
+        if ($response->isSuccessful()) {
+            return $response->getCardReference();
+        }
+    }
 }

src/Message/CreateCardRequest.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Omnipay\GiroCheckout\Message;
+
+class CreateCardRequest extends AuthorizeRequest
+{
+    public function getData()
+    {
+        $this->setCreateCard(true);
+
+        return parent::getData();
+    }
+}