PHP：如何使用 SimpleXMLElement 向更深的子注释添加属性

Question

如何使用SimpleXMLElement 将属性添加到更深层的子笔记？例如，

$xml = new SimpleXMLElement('<xml/>');

$response = $xml->addChild('response');
$response->addChild('error');
$response->addAttribute('elementid', 100);
$response->addAttribute('message', 'You must not leave this field empty!');


Header('Content-type: text/xml');
print($xml->asXML());

我明白了，

<xml>
<response elementid="100" message="Key name - You must not leave this field empty!">
<error />
</response>
</xml>

但其实我想要，

<xml>
<response>
<error elementid="100" message="Key name - You must not leave this field empty!" />
</response>
</xml>

有可能吗？

Answer 1

<?php
$xml = new SimpleXMLElement('<xml/>');

$response   = $xml->addChild('response');
$error      = $response->addChild('error');
$error->addAttribute('elementid', 100);
$error->addAttribute('message', 'You must not leave this field empty!');

Header('Content-type: text/xml');
print($xml->asXML());