NodeCollapsed プロパティ (DataTreeClientEvents)

// The client event 'NodeCollapsed' takes two parameters sender and e
    // sender  is the object which is raising the event
    // e is the DataTreeNodeEventArgs
function WebDataTree_NodeCollapsed(sender ,e) {
    //Gets the node object that is collapsed
    var node = e.getNode();

    //Gets the text of the node
    var nodeText = node.get_text();

    alert("Node '" + nodeText + "' collapsed!");
}