This function inserts the new node newnode right before the node refnode. The return value is
the inserted node. If you plan to do further modifications on
the appended child you must use the returned node.
(PHP = 4.3 only) If
newnode already is part of a document, it will be
first unlinked from its existing context. If refnode is NULL, then newnode will be inserted at the end
of the list of children.
domnode_insert_before() is very
similar to domnode_append_child() as
the following example shows which does the same as the
example at
domnode_append_child().
See also
domnode_append_child().