php - Xpath setAttribute fatal error 调用成员函数setAttribute

Question

我正在记录来自 API 调用的错误请求/响应。为了将日志存储在数据库中，我想用 * 替换信用卡号码。

请求 XML 如下所示:

<xml>
    <request servicekey="service key" branchcode="branch" language="EN" postalcode="Postal Code" country="CA" email="<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="fe9b939f9792be9b869f938e929bd09d9193" rel="noreferrer noopener nofollow">[email protected]</a>">
        <paxes>
            <pax id="1" birthdate="19790215" firstname="John" lastname="Smith" />
            <pax id="2" birthdate="19800828" firstname="Jane" lastname="Smith" />
        </paxes>
        <plans>
            <plan code="Plan Code" >
                <paxes>
                    <pax id="1" sumins="1200.00" />
                    <pax id="2" sumins="1480.31" />
                </paxes>
            </plan>
        </plans>
        <payments>
            <payment amount="246.24" type="VI" ccnum="4111111111111111" ccexp="0711" ccname="John Smith" />
        </payments>
    </request>
</xml>

从这里，我只需获取支付节点和 ccnum 属性即可对其进行编辑(xml 保存为 $requestXML):

$_req = new DOMDocument();
$_req->loadXML($requestXML);
$_xpathReq = new DOMXPath($_req);
$_reqDom = $_xpathReq->query("/xml/request/payments/payment");
$_reqDom->item(0)->setAttribute('ccnum','*****');
$requestXML = $_req->saveXML();    

它按预期工作，xml中的CC号被替换为*'s

$responseXML 略有不同:

<string xmlns="http://tempuri.org/">
    <xml>
        <request servicekey="service key" branchcode="branch code" language="EN" postalcode="Postal Code" country="CA" email="<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="67020a060e0b27021f060a170b024904080a" rel="noreferrer noopener nofollow">[email protected]</a>">
            <paxes>
                <pax id="1" birthdate="19790215" firstname="John" lastname="Smith" />
                <pax id="2" birthdate="19800828" firstname="Jane" lastname="Smith" />
            </paxes>
            <plans>
                <plan code="Plan Code">
                    <paxes>
                        <pax id="1" sumins="1200.00" />
                        <pax id="2" sumins="1480.31" />
                    </paxes>
                </plan>
            </plans>
            <payments>
                <payment amount="246.24" type="VI" ccnum="4111111111111111" ccexp="0711" ccname="John Smith" />
            </payments>
        </request>
        <response>
            <errors>
                <error>Purchase Card Processing was not approved [-1]:Cancelled: null | CARD: **** | Exp: 1407 | Amount: $246.24</error>
            </errors>
        </response>
    </xml>
</string>

与之前的想法相同，我运行了一段非常相似的 PHP 代码:

$_req = new DOMDocument();
    $_req->loadXML($responseXML);
    $_xpathReq = new DOMXPath($_req);
    $_reqDom = $_xpathReq->query("/string/xml/request/payments/payment");
    $_reqDom->item(0)->setAttribute('ccnum','*****');
    $responseXML = $_req->saveXML(); 

但是当我运行这个时，我得到 fatal error :在非对象上调用成员函数 setAttribute() ，它指向包含 $_reqDom->item(0 )->setAttribute('ccnum','*****');

这两个 xml 之间的唯一区别是其中一个包含在字符串节点中，并且有一个表示响应的额外节点。我想我可以解决这个问题(只需拉出响应节点并将其附加到请求 xml 中)，但我现在的使命是让这种方式发挥作用。

Answer 1

问题是由于响应 xml 中的命名空间造成的。您必须使用 XPath 选择器注册 rootNamespace。以下代码将起作用:

$response = new DOMDocument();
$response->loadXML($responseXml);
$selector = new DOMXPath($response);

// get the root namespace
$rootNamespace = $response->lookupNamespaceUri(
    $response->namespaceURI
);
// and register it with $selector. I'm using 'x' as the prefix
// you are free to use a different prefix
$selector->registerNamespace('x', $rootNamespace);

// You won't need to specify the whole path. You could just grab 
// all payment node regardless of their location in the xml tree
$result = $selector->query('//x:payment');
foreach($result as $node) {
    $node->setAttribute('ccnum', '*****');
}

$responseXml = $response->saveXML();
echo $responseXml;