# Expanding Nodes

Here are some general rules when expanding nodes:

1. The server-side method **ExpandAllNodes()** will expand only the nodes that have **ExpandMode** set to **ClientSide**. The same applies when you set the **Expanded** property to *True*.

Nodes that have any other **ExpandMode** can be expanded only client-side: either by user interaction (mouse click) or by calling the **expand()** client-side method.

As a result, if you set the **Expanded = true** to a node which has **ExpandMode** - **ServerSideCallBack/ServerSide/WebService** - the node will not expand and the **NodeExpand** server-side event will **not fire**.

2. Setting the **Expanded** property to *True* does not fire the [NodeExpand](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/server-side-programming/events/nodeexpand) event. You can place the code that is to be executed in that event right after setting the Expanded property to True.

3. Calling the client-side **expand()** method does not fire **OnClientNodeExpanding** and **OnClientNodeExpanded** client-side events.

This is by design. You can put your code from the **OnClientNodeExpanding** handler before calling the expand() method and the code from the **OnClientNodeExpanded** after the call of the expand() method.

If the node which is expanding has set **ExpandMode** to either **ServerSideCallBack** or **WebService** - the [OnClientNodePopulating](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/events/onclientnodepopulating) and [OnClientNodePopulated](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/events/onclientnodepopulated) client-side events are fired.