Is there an equivalent of clearAll() in dhtmlXtree? 

Is there an equivalent of clearAll() in
dhtmlXtree? 

Basically, under certain conditions I want to
invoke loadXML again to get latest state from server. But prior to that I want
to clear the old tree.

There is a deleteChildItems method. Try to use next
approach:

           
tree.deleteChildItems(0);

It deletes all items in tree, and all related to them data (basically
the same as clearAll), and you can load new data from XML after that.