如何设置SimpleXmlElement的文本值而不使用其父项？

Question

我想设置（）与XPath发现了一些节点的文本

<?php 

$args = new SimpleXmlElement(
<<<XML 
<a> 
    <b> 
    <c>text</c> 
    <c>stuff</c> 
    </b> 
    <d> 
    <c>code</c> 
    </d> 
</a> 
XML 
); 

// I want to set text of some node found by xpath 
// Let's take (//c) for example 

// convoluted and I can't be sure I'm setting right node 
$firstC = reset($args->xpath("//c[1]/parent::*")); 
$firstC->c[0] = "test 1"; 

// like here: Found node is not actually third in its parent. 
$firstC = reset($args->xpath("(//c)[3]/parent::*")); 
$firstC->c[2] = "test 2"; 

// following won't work for obvious reasons, 
// some setText() method would be perfect but I can't find nothing similar, 
$firstC = reset($args->xpath("//c[1]")); 
$firstC = "test"; 

// maybe there's some hack for it? 
$firstC = reset($args->xpath("//c[1]")); 
$firstC->{"."} = "test"; // nope, just adds child named . 
$firstC->{""} = "test"; // still not right, 'Cannot write or create unnamed element' 
$firstC["."] = "test"; // still no luck, adds attribute named . 
$firstC[""] = "test"; // still no luck, 'Cannot write or create unnamed attribute' 
$firstC->addChild('','test'); // grr, 'SimpleXMLElement::addChild(): Element name is required' 
$firstC->addChild('.','test'); // just adds another child with name . 

echo $args->asXML(); 

// it outputs: 
// 
// PHP Warning: main(): Cannot add element c number 2 when only 1 such elements exist 
// PHP Warning: main(): Cannot write or create unnamed element 
// PHP Warning: main(): Cannot write or create unnamed attribute 
// PHP Warning: SimpleXMLElement::addChild(): Element name is required 
// <?xml version="1.0"? > 
// <a> 
// <b> 
// <c .="test">test 1<.>test</.><.>test</.></c> 
// <c>stuff</c> 
// </b> 
// <d> 
// <c>code</c> 
// <c>test 2</c></d> 
// </a> 

Answer 1

您可以用的SimpleXMLElement自我参照做：

$firstC->{0} = "Victory!!"; // hackity, hack, hack! 
// -or- 
$firstC[0] = "Victory!!"; 

看着

var_dump((array) reset($xml->xpath("(//c)[3]"))) 

后发现

这也适用unset操作，如an answer to中所述：

• Remove a child with a specific attribute, in SimpleXML for PHP

Answer 2

真正的答案是：你有种不能。

另一方面，您可以使用DOM，例如，

dom_import_simplexml($node)->nodeValue = 'foo';