DOM Parser- CDATA Query

$dom = new DOMDocument('1.0');
$Rootelement = $dom->createElement('Domain', 'Root element');
$dom->appendChild($Rootelement);

$extraInfo=$dom->createElement('extrainfo');
$Rootelement->appendChild($extraInfo);

$rootTextNode=$dom->createTextNode("Co > S&S ");
$extraInfo->appendChild($rootTextNode);

header ("Content-Type:text/xml"); 
echo $dom->saveXML();

I was trying an example for CDATA Section in DOM and got stuck here. I have created a '' xml node which contains illegal characters like '>' ,'&' but when I see the output of above code browsers do not throw an error saying usage of illegal characters or XML is not well formed.... I remember that this error use to pop 开发者_开发百科up if you do not keep these characters in CDATA Section.

Can someone help me what I am missing.. As per me it should give me some error in browser but I am receiving correct output !!!

Regards, Priti

You are programatically constructing a DOM and then converting it to XML.

The library you are using will either wrap the text node in a CDATA section, or represent the characters with special meaning in XML with entities (> etc). Either is valid and equivalent.

This is also why we use XML libraries instead of templates to build XML documents. They take care of all of that for us and stop us ending up with non-well-formed documents.