How to write CDATA using SimpleXmlElement?

I have this code to create and update xml file:

<?php
$xmlFile    = 'config.xml';
$xml        = new SimpleXmlElement('<site/>');
$xml->title = 'Site Title';
$xml->title->addAttribute('lang', 'en');
$xml->saveXML($xmlFile);
?>

This generates the following xml file:

<?xml version="1.0"?>
<site>
  <title lang="en">Site Title</title>
</site>

The question is: is there a way to add CDATA with this method/technique to create xml code below?

<?xml version="1.0"?>
<site>
  <title lang="en"><![CDATA[Site Title]]></title>
</site>

Got it! I adapted the code from this great solution (archived version):

    <?php
    
    // http://coffeerings.posterous.com/php-simplexml-and-cdata
    // https://web.archive.org/web/20110223233311/http://coffeerings.posterous.com/php-simplexml-and-cdata
    
    // Customized 'SimpleXMLElement' class.
    class SimpleXMLExtended extends SimpleXMLElement {
    
      // Create CDATA section custom function.
      public function addCData( $cdata_text ) {
        $node              = dom_import_simplexml( $this ); 
        $ownerDocumentNode = $node->ownerDocument;
        
        $node->appendChild( $ownerDocumentNode->createCDATASection( $cdata_text )); 
      }
    
    }
    
    // How to create the following example, below:
    // <?xml version="1.0"?>
    // <site>
    //   <title lang="en"><![CDATA[Site Title]]></title>
    // </site>
    
    /*
     * Instead of SimpleXMLElement:
     * $xml = new SimpleXMLElement( '<site/>' );
     * create from custom class, in this case, SimpleXMLExtended.
    */
    
    // Name of the XML file.
    $xmlFile    = 'config.xml';

    // <?xml version="1.0"?>
    // <site></site>
    // ^^^^^^^^^^^^^
    $xml        = new SimpleXMLExtended( '<site/>' );
    
    // Insert '<title><title>' into '<site></site>'.
    // <?xml version="1.0"?>
    // <site>
    //   <title></title>
    //   ^^^^^^^^^^^^^^^
    // </site>
    $xml->title = NULL; // VERY IMPORTANT! We need a node where to append.
    
    // CDATA section custom function.
    // <?xml version="1.0"?>
    // <site></site>
    // <title><![CDATA[Site Title]]></title>
    //        ^^^^^^^^^^^^^^^^^^^^^^
    // </site>
    $xml->title->addCData( 'Site Title' );
    
    // Add an attribute.
    // <?xml version="1.0"?>
    // <site></site>
    //   <title lang="en"><![CDATA[Site Title]]></title>
    //          ^^^^^^^^^^
    // </site>
    $xml->title->addAttribute( 'lang', 'en' );
    
    // Save.
    $xml->saveXML( $xmlFile );
    
    ?>

XML file, config.xml, generated:

    <?xml version="1.0"?>
    <site>
      <title lang="en"><![CDATA[Site Title]]></title>
    </site>

Thank you Petah, hope it helps!