In load on demand scenario when you expand the parent node and load its nodes the expand mode of the parent node is changed to ClientSide. This means that if you collapse that node and expand it again - no request will be made to the web service and the NodeExpand server event will not fire.
Sometimes you may need to refresh the nodes that are already added via load on demand - for example because the DataSource has changed. Here is how:
- Collapse the parent node using the collapse() method:
- Clear its nodes and set its expand mode to either ServerSideCallBack or WebService:
node.get_treeView().trackChanges(); node.get_nodes().clear(); node.set_expandMode(Telerik.Web.UI.TreeNodeExpandMode.WebService); node.get_treeView().commitChanges();
Here I am using node.get_treeView() method to get a reference to the TreeView client object, but if you already have a reference to that object (e.g. via the sender object in the client events) you can use that.