DomNode->replace_node

(PHP 4.2) This function replaces an existing node with the passed new node. Before the replacement newnode is copied if it has a parent to make sure a node which is already in the document will not be inserted a second time. This behaviour enforces doing all modifications on the node before the replacement or to refetch the inserted node afterwards with functions like domnode_first_child(), domnode_child_nodes() etc..

(PHP 4.3) This function replaces an existing node with the passed new node. It is not copied anymore. If newnode was already inserted in the document it is first unlinked from its existing context. If the replacement succeeds the old node is returned.

See also domnode_append_child()