php - 如何通过xpath获取每个节点的属性

Question

如何通过xpath获取每个节点的属性？

例如，

book.xml，

<?xml version="1.0" encoding="UTF-8" ?>
<records timestamp="1264777862">
<record></record>
<record></record>
<record timestamp="1264777000"></record>
<record></record>
</records>

php，

<?php

$doc = new DOMDocument;

$doc->load('book.xml');

$xpath = new DOMXPath($doc);

# get and output "<entry>" elements
$x = $doc -> getElementsByTagName('record');

# Count the total feed with xpath.
$total = $x->length;

# the query is relative to the records node
$query = 'string(/records/@timestamp)';

for ($i=0; $i<$total; $i++)
{
    $timestamp = $xpath->evaluate($query,$x->item($i));
    echo $timestamp ."<br/>";
}

?>

结果（仅循环第一个节点），

1264777862
1264777862
1264777862
1264777862

但我想得到

1264777862
1264777000

我已经按照here的问题和答案进行了修改。

也许有更好的方法？

编辑：

xml，

<?xml version="1.0" encoding="UTF-8" ?>
<records>
    <record timestamp="1264777862">A</record>
    <record>B</record>
    <record timestamp="1264777000">C</record>
    <record>D</record>
</records>

有了这个，

for ($i=0; $i<$total; $i++)
{
    $value = $x->item($i)->childNodes->item(0)->nodeValue;
    $timestamp = $xpath->evaluate($query,$x->item($i));
    echo $value.': '.$timestamp ."<br/>";
}

我得到这个结果，

A: 1264777862
B: 1264777862
C: 1264777862
D: 1264777862

但这是我追求的结果

A: 1264777862
B: 
C: 1264777862
D: 

编辑：

一个测试，

$nodes = $xpath->query('//records/record');

foreach($nodes as $node) {
    $value = $node->nodeValue;
    $timestamp = $node->getAttribute('timestamp');
    echo $value .': '."<br/>";
}

结果，

A: 
B: 
C: 
D: 

Answer 1

一种方法：

$nodes = $xpath->query('//records[@timestamp]');
foreach($nodes as $node) {
    $timestamp = $node->getAttribute('timestamp');
}

不过，您在示例中混合了record和records，因此我不确定您实际使用的是哪个。



更新：此代码对我有用：

<?php

$xml = <<<EOL
<?xml version="1.0" encoding="UTF-8" ?>
<records>
    <record timestamp="1264777862">A</record>
    <record>B</record>
    <record timestamp="1264777000">C</record>
    <record>D</record>
</records>
EOL;

$x = new DOMDocument();
$x->loadXML($xml);

$xp = new DOMXpath($x);

$nodes = $xp->query('//records/record');
foreach($nodes as $node) {
   echo $node->nodeValue, ': ', $node->getAttribute('timestamp'), "\n";
}

和输出

A: 1264777862
B:
C: 1264777000
D: