DevShed continues their series looking at using the DOM extension in PHP5 to work with XML in your application. They've already looked at adding attributes and creating CDATA information in a new DOM document. This time they build on that and also include new methods - appending comment nodes and getting at XML nodes by their IDs.

I'm talking about the DOM XML extension, which allows you to handle XML documents by using the DOM API. Thus, if you're interested in learning how to put this extension to work for you quickly, look no further, because you've come to the right place. [...] In this third installment of the series, I'll be teaching you specifically how to append comment nodes to a given XML string and how to extract certain elements via their IDs.

They review the method to add attributes and CDATA to an XML document first. Then they cover the other two new topics - appending comment nodes and grabbing nodes by their ID attribute.