createCDATASection is undefined when generating XML - php

Question

I'm trying to generate an xml file using PHP, with the the description element being placed on a CDATA.
<?php
$title = "Volvo";
$description = "this is a test description";
$xml = new SimpleXMLElement('<xml/>');
$track = $xml->addChild('blog');
$post = $track->addChild('post');
$post->addChild('title',$title);
$cdata = createDATASection($description);
$post->addChild('description',$cdata);
$xml->asXml();
?>
Am I using createDATASection correctly? I have also tried other ways but I am still not getting it.

Answer 1

createCDATASection() is a method of the DOMDocument. SimpleXML itself is limited. If you need that much control (like creating specific node types) you will have to use DOM. SimpleXML treats the XML as a tree of just elements. In DOM everything is a node, elements, texts, attributes, comments, ...
In DOM the create and the append are separate. You create an new node (of any type) with the corresponding method of DOMDocument then you append it using the method of the parent node. The append methods will return the node, so you can nest calls.
Here is your example source converted to DOM API calls:
$title = "Volvo";
$description = "this is a test description";
$document = new DOMDocument();
$xml = $document
->appendChild($document->createElement('xml'));
$blog = $xml
->appendChild($document->createElement('blog'));
$track = $blog
->appendChild($document->createElement('track'));
$post = $track
->appendChild($document->createElement('post'));
$post
->appendChild($document->createElement('title'))
->appendChild($document->createTextNode($title));
$post
->appendChild($document->createElement('description'))
->appendChild($document->createCDATASection($description));
$document->formatOutput = TRUE;
echo $document->saveXml();
Output:
<?xml version="1.0"?>
<xml>
<blog>
<track>
<post>
<title>Volvo</title>
<description><![CDATA[this is a test description]]></description>
</post>
</track>
</blog>
</xml>