Yes, this approach was just a workaround in this specific case, since there was not setDataPath client-side methods in the public API, so it is not guaranteed that it would work in all cases.

Still, I am glad that you managed to find another solution and especially that you shared it in our public forums - I am sure many other people will find it useful as well.

Interestingly this DOES NOT WORK when DemandLoad="Manual"!

 Without changing anything in my code except the DemandLoad parameter, the e.node.DataPath on the server-side was "".

 Very strange, but I coded around it by setting the DataPath on the server-side while building the nodes initially.

Thank you!  That resolved my issue.

Hello,

Yes, I see. This is a good question, by the way. So yes, you are correct, in the public CSOM unfortunately there is no public setDataPath method. Point taken, we might add this in the future. We do have getDataPath though, and I went through the source code to check it out and here is the source:

 this.getDataPath = function() {
            return this.element.getAttribute("igPath");
        }

Based on that, I decided that changing the igPath attribute in the DemandLoad client-side event might work, and voila, it indeed worked (at least in my case). Here is the client-side code that changes DataPath and changes are persisted to the server. Hope this works for you.

       function Load(menuId, itemId) {
            var node = igtree_getNodeById(itemId);
            node.Element.setAttribute("igPath", "testValue") 

        }

I guess I did not make myself clear.

The server creates the top level node and it contains a Tag.  When the node is expanded, the server side code creates child nodes which contain Tags.  However, when one of these nodes is expanded the Tag is not passed to the server.  I can trap the client-side DemandLoad and I see the tag is in the node and it contains the tag (i.e.,  igtree_getNodeById(itemId).getTag()).  However, the node on the server side looks like this:

?e.Node
{Infragistics.WebUI.UltraWebNavigator.Node}
    CheckBox: NotSet {2}
    Checked: False
    CssClass: Nothing
    DataBound: False
    DataItem: Nothing
    DataKey: Nothing
    DataPath: "127:2<2>dir<2>8<1>"
    Enabled: True
    Expanded: False
    FirstNode: Nothing
    Hidden: False
    HiliteClass: ""
    HoverClass: ""
    Images: {Infragistics.WebUI.UltraWebNavigator.NodeImageUrls}
    ImageUrl: ""
    Index: 0
    IslandClass: ""
    Level: 0
    LoadOnDemand: False
    Margin: {Infragistics.WebUI.Shared.Margin}
    NextNode: Nothing
    NextVisible: Nothing
    Nodes: {Infragistics.WebUI.UltraWebNavigator.Nodes}
    Padding: {Infragistics.WebUI.Shared.Padding}
    Parent: Nothing
    PrevNode: Nothing
    PrevVisible: Nothing
    Selected: {"Object reference not set to an instance of an object."}
    SelectedImageUrl: ""
    ShowExpand: False
    Style: {Infragistics.WebUI.Shared.Style}
    Styles: {Infragistics.WebUI.Shared.Style}
    Tag: Nothing
    TagString: Nothing
    TargetFrame: Nothing
    TargetUrl: Nothing
    Text: Nothing
    Title: Nothing
    ToolTip: Nothing

Note that the DataPath contains information where nothing else does!  This, along with the Tag and everything else, is set on the server side in the initial DemandLoad.  My logic on the Server-side checks to see if e.node.Tag IS NOTHING, and uses the DataPath instead.  This works fine, but I want to pass additional client-side status information to the server, thus I want to setDataPath.

 Just for grins I added a igtree_getNodeById(itemId).setTag("xxx") in the client-side DemandLoad, but I did not see the xxx on the server-side.

Hope this clarifies my desire to setDataPath.