DOMDocument replace text with link

function replace_text_with_link($dom, $text, $link){
  $query = new DOMXPath($dom);
  $nodeList = $query->query("//text()[contains(., '".$text."')]");
  foreach ($nodeList as $node) {
    $span = $dom->createElement('span', $node->nodeValue);
    $a = $dom->createElement('a', $text);
    $a->setAttribute('href',$link);
    if(!$node->parentNode->getAttribute('href') && !$node->parentNode->getAttribute('href')){
        $node->parentNode->replaceChild($a, $node);
        $a->appendChild($span);
    }
  }
  return $dom;
}