(PHP 5 >= 5.2.0)
DOMNode::C14N — Canonicalize nodes to a string
$exclusive
   [, bool $with_comments
   [, array $xpath
   [, array $ns_prefixes
  ]]]] )Canonicalize nodes to a string
exclusiveEnable exclusive parsing of only the nodes matched by the provided xpath or namespace prefixes.
with_commentsRetain comments in output.
xpathAn array of xpaths to filter the nodes by.
ns_prefixesAn array of namespace prefixes to filter the nodes by.
   Returns canonicalized nodes as a string or FALSE on failure