PHP XML DOMDocument

I am trying to save and load xml files (including append etc) using php in my php file here:

Code:

---

<?php
$xmlclass = new xml();

class xml{
        private $file;
        private $xml;
       
        public function getfile(){
                return $this->file;
        }
        public function setfile($name){
                $this->file = $name;
        }
        private function readyXML(){
                $this->xml = new DOMDocument();
        }
        public function createXML(){
                $this->readyXML();
                $this->saveXML();
        }
       
        public function addElement($node, $text){
                $this->loadXML();
                $ele = $this->xml->createElement($node);
            $ele->nodeValue = $text;
            $this->xml->appendChild($ele);       
                $this->saveXML();
        }
       
        public function removeElement(){
                $this->loadXML();
        }
       
        public function countElement($node){
                $this->loadXML();
                return $this->xml->getElementsByTagName($node)->length;
        }
       
        private function loadXML(){
                $this->readyXML();
                $this->xml->loadXML($this->file);
        }
       
        private function saveXML(){
                $this->xml->save($this->file);
        }
}

?>

---

Calling the code here:

Code:

---

<?php
require 'php/xml.php';

$file = 'xml/test.xml';
$xmlclass->setfile($file);

if(!file_exists($xmlclass->getfile()))
        $xmlclass->createXML();

$xmlclass->addElement('message','text testing 1');
$xmlclass->addElement('message','text testing 2');

?>

---

However, I keep getting errors like this:
Warning: DOMDocument::loadXML(): Start tag expected, '<' not found in Entity, line: 1 in C:\xampp\htdocs\Websites\XML Tester\php\xml.php on line 41

Also it seems that addElement doesnt add the element and just over writes it.