Update xml namespaces with data from a PHP form

Question

In the example below, the PHP form updates the XML with the text entered in the fields.

XML file labela.xml:

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

The PHP form used to change the "change1" and "change2" in the XML file

<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>

How do I extract and update the strings change1 and change2 from the XML structure below, using PHP?

<?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>

thanks in advance to everyone who takes their time to help

Answer 1

The ideal is to extract data from your XML using XPath. You will get what you want by proceeding as follows:

load.php

<?php
$change1 = $_POST['change1'];
$change2 = $_POST['change2'];
$change3 = $_POST['change3'];   
$xml = simplexml_load_file('your_complex_xml.xml');
$xml->xpath('//pt:data')[0][0] = $change1;
$xml->xpath('//pt:data')[1][0] = $change2;
$xml->xpath('//pt:data')[2][0] = $change3;
$xml->asXML('new_complex_xml.xml');

form.php

    <form method="post" action="load.php">
    <label for="change1">change1:</label>
    <input type="text" name="change1" id="change1"><br>
    <label for="change2">change2:</label>
    <input type="text" name="change2" id="change2"><br>
    <label for="change3">change3:</label>
    <input type="text" name="change3" id="change3"><br>
    <input type="submit" value="Generate New XML">
    </form>

If you still can't, tell me which part you're having trouble with. I wish you success in your projects.