php - 如何将 child 添加到特定节点

Question

这是我的起始 xml:

 <?xml version="1.0" encoding="utf-8"?>
    <root>
      <child>
        <children></children>
     </child>
    </root>

我想在 child 中添加其他 child ？？但我正在尝试，没有什么我不知道如何...:S help pls 我想让我的 xml 像这样

  <?xml version="1.0" encoding="utf-8"?>
    <root>
      <child>
        <children></children>
        <children></children>
     </child>
    </root>

这是我的代码:

<?php
            $dom = new DomDocument;
            //$dom->preserveWhiteSpace = FALSE;
            $dom->load("myXML.xml");
            $root = $dom->getElementById('root');
            $params = $dom->getElementsByTagName('child');
            $cantidadCategorias = $params->length+1;

            $newElement = $dom->createElement('child','');
            $dom->appendChild($newElement);
            $f = fopen("myXML.xml",'w+'); 
            fwrite($f,$dom->saveXML()); 
            fclose($f); 

Answer 1

与 DOMDocument就这么简单:

$child = new DOMElement('children');
$parent->appendChild($child);

而 $parent 是 DOMElement 父级，(在您更新问题之后)获取是您问题的一部分:

// append <children> to the first <child> element
$parent = $dom->getElementsByTagName('child')->item(0);
$child = new DOMElement('children');
$parent->appendChild($child);