It took me forever to find a mapping for the XML_*_NODE constants. So I thought, it'd be handy to paste it here:
 1 XML_ELEMENT_NODE
 2 XML_ATTRIBUTE_NODE
 3 XML_TEXT_NODE
 4 XML_CDATA_SECTION_NODE
 5 XML_ENTITY_REFERENCE_NODE
 6 XML_ENTITY_NODE
 7 XML_PROCESSING_INSTRUCTION_NODE
 8 XML_COMMENT_NODE
 9 XML_DOCUMENT_NODE
10 XML_DOCUMENT_TYPE_NODE
11 XML_DOCUMENT_FRAGMENT_NODE
12 XML_NOTATION_NODE