Accessing Client Changes on the Server Side

Client side changes are available on the server side after postback. You can use the ClientChanges property of RadTreeView to access them. The ClientChanges property of RadTreeView returns a collection of objects of type ClientOperation. An operation has two properties:

• Item - the item which has been affected by the client operation;

• Type - the type of the operation which is one of the following four cases:

  • Update - when a property is set on the the client through methods such as set_text(), set_value(), enable(), disable(), etc.: treeNode.disable();

  • Remove - when the remove client method is called: treeview.get_nodes().remove(treeNode);

  • Insert - when the addclient method is called: treeview.get_nodes().add(treeNode);

  • Clear - when a node with child nodes calls the clear() method: parentNode.get_nodes().clear(). If the parent node has no child nodes, the ClientChanges collection is not altered.

Note that you need to call the trackChanges() and commitChanges() client methods of RadTreeView in order to be able to access the changes on the server via the ClientChanges property.

Example:

The code snippet below enumerates through all operations in the ClientChanges collection and utilizes both the Item and Type properties. For a complete demo, please see the client-side Add/Remove/Disable Items example.

foreach (ClientOperation<RadTreeNode> operation in RadTreeView1.ClientChanges)
{
    RadTreeNode node = operation.Item;

    switch (operation.Type)
    {
        case ClientOperationType.Insert:
            break;
        case ClientOperationType.Remove:
            break;
        case ClientOperationType.Update:
            UpdateClientOperation<RadTreeNode> update = operation as UpdateClientOperation<RadTreeNode>;
            break;
        case ClientOperationType.Clear:
            break;
    }
}

For Each operation As ClientOperation(Of RadTreeNode) In RadTreeView1.ClientChanges

Dim node As RadTreeNode = operation.Item

 Select Case operation.Type
  Case ClientOperationType.Insert
   Exit Select
  Case ClientOperationType.Remove
   Exit Select
  Case ClientOperationType.Update
    Dim update As UpdateClientOperation(Of RadTreeNode) = 
        TryCast(operation, UpdateClientOperation(Of RadTreeNode))
   Exit Select
  Case ClientOperationType.Clear
   Exit Select
 End Select
Next

See Also

• RadTreeView