Cancel Postback when collapsing a Node

[Duy]

I read in the documentation that "Every collapse of a node causes a postback if the ExpandMode is set to ServerSide." Is there a way of canceling the postback? I tried this javascript function but it doesn't work.

(I set the ExpandMode on the c# code behind that isn't shown here)

  function ClientNodeCollapsed(sender, eventArgs) {
       var node = eventArgs.get_node();
       
       if (node)
       {
            node.collapse();
       }
    return false;
   }
  
.aspx side:

                <telerik:RadTreeView id="TreeVw" runat="server" OnClientNodeClicked="ClientNodeClicked" OnClientNodeCollapsed="return ClientNodeCollapsed(sender, eventArgs)"

This results in a javascript error. Can anyone help?

[Veselin Vasilev]

Hello Duy,

Actually you need to subscribe to the OnClientNodeCollapsing event and cancel it.

Sincerely yours,
Veselin Vasilev
the Telerik team

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[Duy]

What I want is for the node to collapse on client side but still expand on server side.

I subscribed to the OnClientNodeCollapsing event and here is my javascript function:

function ClientNodeCollapsing(sender, eventArgs) {
        var node = eventArgs.get_node();
        node.collapse();
        eventArgs.set_cancel(true);
   }

ASPX:

 <telerik:RadTreeView id="LevelTreeVw" runat="server" OnClientNodeClicked="ClientNodeClicked" OnClientNodeCollapsing="ClientNodeCollapsing"
                    OnNodeExpand="LevelTreeVw_NodeExpand" AutoPostBack="true" height="300" width="370">
                </telerik:RadTreeView>

This still seems to postback. Client side code, node.collapse() doesn't seem to collapse without post back. It is the same action if I didn't subscribe to this event. What am I doing wrong?

[Veselin Vasilev]

Hi Duy,

No, you cannot collapse the node and not fire the postback when the expand mode is ServerSide.
If you cancel the OnClientNodeCollapsing event - the postback will not occur, but the node will be expanded.

Kind regards,
Veselin Vasilev
the Telerik team

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Check out the tips for optimizing your support resource searches.