Attach event to specific child in tree

I am creating a tree in which based on which child of a node is clicked the data is loaded in another node. For example
Node1
(-child1
-child2)
Node2
(data not yet loaded)

Based on what user clicks in Node1 (child1 or child2) data will be loaded in Node2.

How to attach events only on children of Node1 and not to the whole tree?

How to attach events only on children of Node1

There’s no way to do such thing, but you can check which item was selected and reload children of the second branch if needed:

http://webix.com/snippet/006f317a