使用 SimpleXML 节点不再存在
尝试使用名为 get_transient 的 WordPress 内置函数缓存 xml 文件，但出现 php 错误：
unserialize() [function.unserialize]: 节点不再存在
//check the db to see if it exists ( get_transient is a WordPress function)
if (false === ($response_xml = get_transient('stats_from_xml_feed'))){
$request_url = "http://example.com/feed.xml";
$request_url = urlencode($request_url);
$response_xml = @simplexml_load_file($request_url);
//kill request if connection problem
if ($response_xml === FALSE){
exit ('could not connect');
} else {
// here we throw it into the WordPress temp DB using set_transient for 12 hours
set_transient('stats_from_xml_feed', $response_xml, 60*60*12);
//some output
$res = $response_xml;
$name = $res->name;
echo $name;
}
Trying to cache an xml file using the build in wordpress function called get_transient but I'm getting a php error:
unserialize() [function.unserialize]: Node no longer exists
//check the db to see if it exists ( get_transient is a WordPress function)
if (false === ($response_xml = get_transient('stats_from_xml_feed'))){
$request_url = "http://example.com/feed.xml";
$request_url = urlencode($request_url);
$response_xml = @simplexml_load_file($request_url);
//kill request if connection problem
if ($response_xml === FALSE){
exit ('could not connect');
} else {
// here we throw it into the WordPress temp DB using set_transient for 12 hours
set_transient('stats_from_xml_feed', $response_xml, 60*60*12);
//some output
$res = $response_xml;
$name = $res->name;
echo $name;
}
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$response_xml是SimpleXMLElement类的实例。SimpleXMLElement不应被（取消）序列化，因为它在其中包装了 资源物体。相反，序列化一些能够在整个过程中幸存下来的东西；来自提要的原始响应、将 XML 加载到
SimpleXMLElement并使用asXML()方法、您想要的（可能是字符串）值的数组，或其他可以序列化的结构。需要考虑的一件事是，您将在“较旧”（宽松地使用该术语）版本的 PHP 中看到
unserialize(): Node no moreexists警告。从 PHP 5.3.2 开始，行为更改为抛出Exception，并显示消息不允许“SimpleXMLElement”序列化。Your
$response_xmlis an instance of theSimpleXMLElementclass. ASimpleXMLElementshould not be (un)serialized, because it wraps a resource within the object.Instead, serialize something which will happily survive the process; the raw response from the feed, all/part of the XML after loading it into the
SimpleXMLElementand using theasXML()method, an array of the (likely string) values you want, or some other structure which is okay to be serialized.One thing to consider is that you will see the
unserialize(): Node no longer existswarning in "older" (to use the term loosely) versions of PHP. As of PHP 5.3.2, the behaviour changed to throw anExceptionwith the messageSerialization of 'SimpleXMLElement' is not allowed.您不应该（不能？）
序列化和反序列化SimpleXML 对象。它是 XML，它首先是一种序列化格式。这里不是盗梦空间！调用
asXML方法获取实际的XML，然后存储它。You shouldn't (can't?)
serializeandunserializethe SimpleXML object. It's XML, which is a serialization format to begin with. This ain't Inception here!Call the
asXMLmethod to get the actual XML, then store that instead.