DOMElement上的PHP DOMXpath查询无法正常工作

Question

I'm trying to run an xpath query to return all elements inside < div class="classB"> with the key_id attribute set. 我正在尝试运行xpath查询以返回设置了key_id属性的<div class =“ classB”>内的所有元素。

<?php
$dom = new DOMDocument;
$dom->loadHTML('
    <html>
    <head></head>
    <body>
        <div class="classA">
            <div key_id="a:1234"></div>
            <div key_id="a:2345"></div>
            <div key_id="a:3456"></div>
            <div class="sub"></div>
            <div class="sub"></div>
        </div>
        <div class="classB">
            <div key_id="b:1234"></div>
            <div key_id="b:2345"></div>
            <div key_id="b:3456"></div>
            <div class="sub"></div>
            <div class="sub"></div>
        </div>
    </body>
    </html>
    ');
$xpath = new DOMXpath ($dom);
$classB = $xpath->query("//*[contains(concat(' ', @class, ' '), ' classB ')]")->item(0);
$subNodes = $xpath->query("//*[@key_id]", $classB);
foreach($subNodes as $elem) {
    var_dump($elem->getAttribute('key_id'));
}
?>

which outputs the following: 输出以下内容：

string(6) "a:1234"
string(6) "a:2345"
string(6) "a:3456"
string(6) "b:1234"
string(6) "b:2345"
string(6) "b:3456"

but I'm trying to get this: 但我试图得到这个：

string(6) "b:1234"
string(6) "b:2345"
string(6) "b:3456"

As you can see, I'm passing the "classB" div as a relative query: 如您所见，我将“ classB” div作为相对查询传递：

$subNodes = $xpath->query("//*[@key_id]", $classB);

My understanding is that query takes an optional domContext of type DOMNode, and $classB is a DOMElement which extends DOMNode. 我的理解是查询采用DOMNode类型的可选domContext，而$ classB是扩展DOMNode的DOMElement。

What am I doing wrong? 我究竟做错了什么？

Answer 1

Try 尝试

$xpath = new DOMXpath ($dom);
$subNodes = $xpath->query("*/div[@class='classB']/div[@key_id]");
foreach($subNodes as $elem) {
    echo $elem->getAttribute('key_id');
}

See demo here 在此处查看演示

DOMElement上的PHP DOMXpath查询无法正常工作

问题描述

1 个解决方案

解决方案1
1 2014-03-03 17:02:29

DOMElement上的PHP DOMXpath查询无法正常工作

问题描述

1 个解决方案

解决方案1 1 2014-03-03 17:02:29

解决方案1
1 2014-03-03 17:02:29