Using xPath on SimpleXmlElement to get single string result

I am trying to get some data from a GoogleCheckout response. I am using a SimpleXmlElement and xpath to search for the data. One of the problems is that the response from xpath is an array of SimpleXmlElements - all I want is the string data. The other is that the response may contain multilpe instances of the TAG name - for example, <email> is shown at least twice but I only want a singe result.

Here is what I have so far

            $notifyData = array();
            $notifyData['buyerEmail'] = $data->xpath('buyer-billing-address//email')[0];
            $notifyData['buyerName'] = $data->xpath('buyer-billing-address//contact-name');
            $notifyData['transactionId'] = $data->xpath('/new-order-notification/google-order-number');
            $notifyData['itemName'] = $data->xpath('//item-name');
            $notifyData['amount'] = $data->xpath('//unit-price');
            $notifyData['currency'] = $notifyData['amount'][0]['currency'];//$data->xpath('//@currency[1]');

here is the response from print_r() on $notifyData

Array
(
    [buyerEmail] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [0] => sandbox@mysite.com
                )

        )

    [buyerName] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [0] => Mr Sandbox Buyer
                )

        )

    [transactionId] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [0] => 271578474675716
                )

        )

    [itemName] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [0] => My Item
                )

        )

    [amount] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [@attributes] => Array
                        (
                            [currency] => USD
                        )

                    [0] => 3.99
                )

        )

    [currency] => SimpleXMLElement Object
        (
            [0] => USD
        )

)

What i want is for the data to show like this after print_r()

Array
(
    [buyerEmail] => sandbox@mysite.com
    ...
    [currency] => USD

Here is an example of an xml response

<new-order-notification xmlns="http://checkout.google.com/schema/2" serial-number="654578974677716-00001-7">

  <buyer-billing-address>

    <address1>19 sandbox st</address1>

    <address2></address2>

    <phone></phone>

    <email>sandbox@mysite.com</email>

    <company-name></company-name>

    <contact-name>Mr Sandbox Buyer</contact-name>

    <fax></fax>

    <country-code>AU</country-code>

    <city>Buyers Town</city>

    <region>VIC</region>

    <postal-code>3460</postal-code>

  </buyer-billing-address>

  <timestamp>2010-10-24T04:25:41.723Z</timestamp>

  <google-order-number>298578974677716</google-order-number>

  <shopping-cart>

    <items>

      <item>

        <digital-content>

          <key is-encrypted="true">PWWoqHo+FtfTi5vHmquOFTFNb4DwNjInAxkW89PLxtU=</key>

          <description>Follow the instructions</description>

          <url>http://mysite.com</url>

        </digital-content>

        <item-name>my product</item-name>

        <item-description>my product</item-description>

        <unit-price currency="USD">3.99</unit-price>

        <quantity>1</quantity>

      </item>

    </items>

  </shopping-cart>

  <order-adjustment>

    <merchant-codes />

    <total-tax currency="USD">0.0</total-tax>

    <adjustment-total currency="USD">0.0</adjustment-total>

  </order-adjustment>

  <buyer-id>634168749882822</buyer-id>

  <buyer-marketing-preferences>

    <email-allowed>true</email-allowed>

  </buyer-marketing-preferences>

  <开发者_开发百科buyer-shipping-address>

    <address1>19 sandbox st</address1>

    <address2></address2>

    <phone></phone>

    <email>sandbox@mysite.com</email>

    <company-name></company-name>

    <contact-name>Mr Sandbox Buyer</contact-name>

    <fax></fax>

    <country-code>AU</country-code>

    <city>Buyers Town</city>

    <region>VIC</region>

    <postal-code>3460</postal-code>

  </buyer-shipping-address>

  <order-total currency="USD">3.99</order-total>

  <fulfillment-order-state>NEW</fulfillment-order-state>

  <financial-order-state>REVIEWING</financial-order-state>

</new-order-notification>

You don't necessarily need xpath here. E.g.

$notifyData = array(
  'buyerEmail' => (string)$data->{'buyer-billing-address'}->email[0],
  'buyerName' => (string)$data->{'buyer-billing-address'}->{'contact-name'}[0],
  'transactionId' => (string)$data->{'google-order-number'}[0]
);
var_dump($notifyData);


function getData() {
  return <<< eox
<new-order-notification xmlns="http://checkout.google.com/schema/2" serial-number="654578974677716-00001-7">
...
</new-order-notification>
eox;
}

prints

array(3) {
  ["buyerEmail"]=>
  string(18) "sandbox@mysite.com"
  ["buyerName"]=>
  string(16) "Mr Sandbox Buyer"
  ["transactionId"]=>
  string(15) "298578974677716"
}

and via foreach you can also handle multiple elements like e.g. <item>

use typecasting:

$notifyData['buyerName'] = (string)$data->xpath('buyer-billing-address//contact-name');