TreeViewExpandChangeEvent

Represents the object of the onExpandChange event (see example).

Name	Type	Default	Description
event	any		The ItemClick event.
item	any		The item that is expanded or collapsed.
itemHierarchicalIndex	string		The hierarchical index of the item. The indices are zero-based. The first root item has a 0 (zero) index. If the first root item has children, the first child acquires a 0_0 index and the second acquires a 0_1 index.