Adding xml node on top of file or reverse the loop - php

Question

I am using xml. Reading the xml-document works fine, adding nodes works fine to but I want the node to add on top of the xml file. Is this possible or is this a nogo?
The reason I want this is because when I display the xml file I want the last added node, displayed as the newest one, on top.
I display the xml with this loop:
foreach($xml->xpath("//user[#id='12345678']") as $user){
foreach($user->children() as $action => $data){
echo"<li>";
echo $data->content;
echo $data->date;
echo"</li>";
}
}
If there is a way to reverse the loop or another way I'm fine with that to, it doesn't have to be adding the first node on top. Below are the file how I add the node and the structure of the xml-file.
Does anyone have an idea how to solve this?
addxml.php
<?php
$file = "actielijst.xml";
$fp = fopen($file, "rb") or die("cannot open file");
$str = fread($fp, filesize($file));
$xml = new DOMDocument();
$xml->formatOutput = true;
$xml->preserveWhiteSpace = false;
$xml->loadXML($str) or die("Error");
// get document element
echo "<xmp>OLD:\n". $xml->saveXML() ."</xmp>";
$root = $xml->documentElement;
$content = $xml->createElement("content");
$contentText = $xml->createTextNode("Nieuwe Factuur Mei");
$content->appendChild($contentText);
$date = $xml->createElement("date");
$dateText = $xml->createTextNode("23-12-2010");
$date->appendChild($dateText);
$action = $xml->createElement("action");
$action->appendChild($date);
$action->appendChild($content);
$root->appendChild($action);
$xml->save("actielijst.xml") or die("Error");
?>
actielijst.xml
<?xml version="1.0"?>
<userid>
-------> Insert new action here <------
<action>
<date>23-01-2010</date>
<content>nieuwe factuur</content>
</action>
<action>
<date>23-01-2010</date>
<content>karten op 01-02</content>
</action>
</userid>

Answer 1

You can use xpath to capture every parent node (action in your case) and then reverse the array...
$users_arr = array_reverse($xml->xpath("action"));
Now you can loop through this array!

Answer 2

This will helps
<?php
$file = "actielijst.xml";
$fp = fopen($file, "rb") or die("cannot open file");
$str = fread($fp, filesize($file));
$xml = simplexml_load_string($str);
$action = $xml->addChild('action');
$action->addChild('content','sundar');
$action->addChild('date','23-12-2010');
header('content-type: application/xml');
echo $xml->saveXML();