XML : php xml_encode set attribute to specific tag name

I xml_encode my array using this code.

  public function xml_encode($mixed, $domElement=null, $DOMDocument=null) {      if (is_null($DOMDocument)) {          $DOMDocument =new DOMDocument;          $DOMDocument->formatOutput = true;          $this->xml_encode($mixed, $DOMDocument, $DOMDocument);          echo $DOMDocument->saveXML();      }      else {          // To cope with embedded objects           if (is_object($mixed)) {            $mixed = get_object_vars($mixed);          }          if (is_array($mixed)) {              foreach ($mixed as $index => $mixedElement) {                  if (is_int($index)) {                      if ($index === 0) {                          $node = $domElement;                      }                      else {                          $node = $DOMDocument->createElement($domElement->tagName);                          $domElement->parentNode->appendChild($node);                      }                  }                  else {                      $plural = $DOMDocument->createElement($index);                      $domElement->appendChild($plural);                      $node = $plural;                      if (!(rtrim($index, 's') === $index)) {                          $singular = $DOMDocument->createElement(rtrim($index, 's'));                          $plural->appendChild($singular);                          $node = $singular;                      }                  }                    $this->xml_encode($mixedElement, $node, $DOMDocument);              }          }          else {              $mixed = is_bool($mixed) ? ($mixed ? 'true' : 'false') : $mixed;              $domElement->appendChild($DOMDocument->createTextNode($mixed));          }      }  }    

https://www.darklaunch.com/2009/05/23/php-xml-encode-using-domdocument-convert-array-to-xml-json-encode

and it works well. Now, I want to set an attribute to a specific tag.

Let's say for example this is my xml.

  <book>       <title>PHP Programming</title>       <description>Learn how to code in PHP</description>  </book>    

I want to set an attribute to title tag and make it

  <title name=attributeValue>         PHP Programming  </title>    

How can I achieve this?

Thanks!