我正在访问YouTube上的gData Api。我将使用this xml作为参考。
我在子SimpleXMLElement对象上使用xpath,但是只搜索子元素及其子元素的xpath,它似乎仍然是从根目录下搜索。
我有以下代码:
<?php
date_default_timezone_set('Australia/Sydney');
$url = "http://gdata.youtube.com/feeds/api/playlists/58FD3A7244B64B99?prettyprint=true&alt=atom&v2=1&fields=title,subtitle,logo,entry%28link%5B@rel=%27alternate%27%5D,id,title,content,author,yt:statistics%29";
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true );
$rawResponse = curl_exec($curl);
$xmlData = simplexml_load_string($rawResponse);
$xmlData->registerXPathNamespace('yt', 'http://gdata.youtube.com/schemas/2007');
foreach($xmlData->entry as $entry) {
var_dump($entry->asXml());
myFunction($entry); die();
}
function myFunction(SimpleXMLElement $xml)
{
var_dump($xml->xpath("//yt:statistics"));
}
而不是预期的:
string(666) "<entry>
<id>http://gdata.youtube.com/feeds/api/playlists/58FD3A7244B64B99/PLlwIr0olq0UxVV_ouqclCE0xRZvs2Lytl</id>
<title type="text">Zero Punctuation on The Escapist</title>
<content type="text">Zero Punctuation picks apart the games so you don't have to. View new episodes every Wednesday only
at http://www.escapistmagazine.com</content>
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=7EpzwuZOvKY&feature=youtube_gdata"/>
<author>
<name>theescapistmagazine</name>
<uri>http://gdata.youtube.com/feeds/api/users/theescapistmagazine</uri>
</author>
<yt:statistics favoriteCount="256" viewCount="188598"/>
</entry>"
object(SimpleXMLElement)#5 (1) {
["@attributes"]=>
array(2) {
["favoriteCount"]=>
string(3) "256"
["viewCount"]=>
string(6) "188598"
}
}
我明白了:
string(666) "<entry>
<id>http://gdata.youtube.com/feeds/api/playlists/58FD3A7244B64B99/PLlwIr0olq0UxVV_ouqclCE0xRZvs2Lytl</id>
<title type="text">Zero Punctuation on The Escapist</title>
<content type="text">Zero Punctuation picks apart the games so you don't have to. View new episodes every Wednesday only
at http://www.escapistmagazine.com</content>
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=7EpzwuZOvKY&feature=youtube_gdata"/>
<author>
<name>theescapistmagazine</name>
<uri>http://gdata.youtube.com/feeds/api/users/theescapistmagazine</uri>
</author>
<yt:statistics favoriteCount="256" viewCount="188598"/>
</entry>"
array(25) {
[0]=>
object(SimpleXMLElement)#5 (1) {
["@attributes"]=>
array(2) {
["favoriteCount"]=>
string(3) "256"
["viewCount"]=>
string(6) "188598"
}
}
[1]=>
object(SimpleXMLElement)#6 (1) {
["@attributes"]=>
array(2) {
["favoriteCount"]=>
string(4) "4787"
["viewCount"]=>
string(7) "1276435"
}
}
[2]=>
object(SimpleXMLElement)#7 (1) {
["@attributes"]=>
array(2) {
["favoriteCount"]=>
string(4) "7628"
["viewCount"]=>
string(7) "1702845"
...
所以,即使我正在处理根元素的子元素,为什么xpath仍在搜索父元素?更重要的是,我如何只搜索子元素?
答案 0 :(得分:5)
您必须在备份时从表达式中删除//
,然后将表达式应用于整个文档。你要找的是一个斜杠/
,它从给定文档片段的根开始。
这应该可以解决问题。 :)
编辑:完全省略斜杠也可以做到这一点。