使用来自 PHP 表单的数据更新 xml 命名空间

在下面的示例中，PHP表单使用在字段中输入的文本更新了XML.

XML文件Labela.xml:

<?xml version="1.0" encoding="UTF-8"?>
<inventors>
   <person>
      <name>change1</name>
      <comment>change2</comment>
   </person>
</inventors>

用于更改XML文件中的"change1"和"change2"的PHP表单

<script src="https://code.jquery.com/jquery-latest.min.js"></script>
 <?php
 $xml = new DOMDocument("1.0", "utf-8");
 $xml->formatOutput = true;
 $xml->preserveWhiteSpace = false;
 $xml->load("labela.xml");

 //Get item Element
 $element = $xml->getElementsByTagName("person")->item(0);

 //Load child elements
 $name = $element->getElementsByTagName("name")->item(0);
 $comment = $element->getElementsByTagName("comment")->item(0);

 //Replace old elements with new
 $element->replaceChild($name, $name);
 $element->replaceChild($comment, $comment);
 ?>

<?php if (isset($_POST["submit"])) {
    $name->nodeValue = $_POST["namanya"];
    $comment->nodeValue = $_POST["commentnya"];
    htmlentities($xml->save("labela.xml"));
} ?>

<form method="POST" action=''>
name <input type="text-name" value="<?php echo $name->nodeValue; ?>" name="namanya" />
comment  <input type="text-comment" value="<?php echo $comment->nodeValue; ?>"  name="commentnya"/>
<input name="submit" type="submit" />
</form>

如何使用PHP从下面的XML struct 中提取和更新字符串change1和change2？

<?xml version="1.0" encoding="UTF-8"?>
<pt:document xmlns:pt="http://schemas.brother.info/ptouch/2007/lbx/main" xmlns:barcode="http://schemas.brother.info/ptouch/2007/lbx/barcode" xmlns:style="http://schemas.brother.info/ptouch/2007/lbx/style" xmlns:text="http://schemas.brother.info/ptouch/2007/lbx/text">
   <pt:body currentSheet="Folha 1">
      <style:sheet name="Folha 1">
         <pt:objects>
            <barcode:barcode>
               <barcode:qrcodeStyle model="2" eccLevel="15%" />
               <pt:data>change1</pt:data>
            </barcode:barcode>
            <text:text>
               <text:textStyle vertical="false" />
               <pt:data>change2</pt:data>
               <text:stringItem charLen="7">
                  <text:ptFontInfo>
                     <text:logFont name="Arial" />
                  </text:ptFontInfo>
               </text:stringItem>
            </text:text>
            <text:text>
               <text:textStyle vertical="false" />
               <pt:data>change3</pt:data>
            </text:text>
         </pt:objects>
      </style:sheet>
   </pt:body>
</pt:document>

提前感谢每一位抽出时间来帮忙的人