[Solved] Treeview OnNodeExpand issue with TreeNodeExpandMode.ServerSideCallBack

[VANDENBERGHE]

Hi everyone,

I have a problem with ServerSideCallback. I want to modify some properties of the node which fired the NodeExpand event in the same one.

        protected void RadTreeView1_NodeExpand(object sender, RadTreeNodeEventArgs e)
        {
            IList<EntityTypeDataContract> list = GetList(e);

            if (list.Count > 0)
            {
                foreach (EntityTypeDataContract type in list)
                {
                    RadTreeNode treeNode = new RadTreeNode(type.DisplayName, type.Value);
                    treeNode.Expanded = false;
                    treeNode.ExpandMode = TreeNodeExpandMode.ServerSideCallBack;
                    e.Node.Nodes.Add(treeNode);
                }
            }
            else
            {
                e.Node.Expanded = false;
                e.Node.ExpandMode = TreeNodeExpandMode.ClientSide;
            }
        }

The problem is until there will be a postback on the page, the state of the triggering node is not change (Expanded = true and ExpandMode = ServerSideCallback). It seems there is no refresh of the already created node during the callback ?

This sample of code works well with ServerSide expand mode but I really need the ServerSideCallBack mode.

Thanks for helping me to solve this problem.

Regards,
Sebastien

[Atanas Korchev]

Hi VANDENBERGHE,

We do not support this capability at the time being. Only the nodes added during the NodeExpand event are updated during ServerSideCallback load on demand. The expanded node does not get updated - setting its properties will not have immediate effect.
In our online demo we have implemented a different technique to find out if a node has children. You can check the implementation of the NodeExpand event. Perhaps you could use the same approach in your application.

Regards,
Albert
the Telerik team

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[VANDENBERGHE]

Thanks for your quick answer.

Regards.