I am trying to add an external library (PHP Simple DOM Parser, http://simplehtmldom.sourceforge.net/index.htm) to a Symfony2 project. I took a tutorial that explains how to incl
You're trying to register a namespace but your class has no namespace. Try adding a namespace to it or use RegisterPrefixes().
BTW: did you know that one of the Symfony components is basically doing the same thing as php simpledom? It's called DomCrawler and it has a support for both xpath and CSS selectors.