RadTreeView OnClientNodeCollapsing

[Graham]

I have a RadTreeView on a page which I have coded as follows:

<telerik:RadTreeView ID="radTreeView" runat="server" Width="100%" AutoGenerateColumns="true" OnNodeClick="radTreeView_OnNodeClick">
<WebServiceSettings Path="BuildTrgMP.aspx" Method="GetChildNodes" />

</telerik:RadTreeView>

I have coded the GetChildNodes webservice call on the server side and this all works fine: when the user clicks a + on the tree, the little whirly appears which the webservice is called to populate the tree, which it does so correctly.
What I want to do is the opposite situation: when the user clicks a - on the tree, I want it to invalidate everything under that node such that the next time the + is clicked, the webservice is again called so that the list is updated from the database.
At the moment clicking the + just reopens the list which has previously been cached in the browser and the webservice is not called to refill the list.
How do I use OnClientNodeCollapsing (or any other approach) to invalidate the list such that pressing + causes the webservice to be called again ?

Thanks
Graham Plowman

[Plamen]

Hi Graham,

 
You can Clear the nodes and reset the expand mode as it is done in the code below: 

function OnClientNodeCollapsing(sender, args) {

           sender.trackChanges();
           args.get_node().get_nodes().clear();
           args.get_node().set_expandMode(Telerik.Web.UI.TreeNodeExpandMode.WebService);
           sender.commitChanges();
       }

Hope this will help you.

Kind regards,
Plamen Zdravkov
the Telerik team

[Graham]

Thanks Plamen.
I've tried that but it doesn't fully work.
If I start at the top of the tree and expand nodes to the lowest level eg:

- TMP Number 1
...- Module1
......- CLO1
.........- MLO1
...+ Module2
...+ Module3
...+ Module4

If I then close the entire structure by clicking the - next to TMP Number 1, followed by pressing its +, then I click Module1 (not its +) I get:

- TMP Number 1
...+ Module1
...Module2
...Module3
...Module4  
...+ Module1
...Module2
...Module3
...Module4  

In other words, the structure is duplicated. If I repeat the close of the root element, then its + and Module1 I get the tree repeated three times.
If I click the + signs to re-expand the tree, all works fine and the tree is populated from the database.
There seems to be a problem with clicking on the actual item text.

If I take out the code you suggested, the duplication no longer happens, but I'm back to my original problem of the tree being cached and not updating from the database.

I'm using 2011.1.519.35

I have no code other than the web service code populating the list:

public static RadTreeNodeData[] GetChildNodes(RadTreeNodeData node) {

int langId = Convert.ToInt32(HttpContext.Current.Session["LangId"]),

orgId =

Convert.ToInt32(HttpContext.Current.Session["OI"]);

KuriousDataContext db = new KuriousDataContext();

// If the node is the root TMP, the node value is the Id of the TMPNode

// record it represents, otherwise, it is the Id of the TMPNodeLink record

// whose child node id points at the node.

List<TMPNodeLink> childNodeList = db.FindTMPNodeLinks(Convert.ToInt32(node.Value)).ToList();

// Work out the node level we are looking at

int level = Convert.ToInt32(node.Attributes["NT"]) + 1;

// Get the first item of the element list which is the element name

var titleElement = db.FindTMPElement(Convert.ToInt32(HttpContext.Current.Session["OI"]), level, CConstants.TMPPR_TITLE);

List<RadTreeNodeData> result = new List<RadTreeNodeData>();

foreach (TMPNodeLink nodeLink in childNodeList) {

RadTreeNodeData childNode = new RadTreeNodeData();

TMPNodeData nodeData = db.FindTMPNodeData(nodeLink.TMPNodeId, titleElement.Id, langId);

childNode.Text = (nodeData ==

null ? "[Not Found]" : nodeData.ValueText);

childNode.Value = nodeLink.Id.ToString();

if (db.HasAnyChildTMPNodes(nodeLink.Id)) {

childNode.ExpandMode =

TreeNodeExpandMode.WebService;

}

else {

// childNode.ExpandMode = TreeNodeExpandMode.ClientSide;

}

//childNode.ImageUrl = NodeTypeImageURL((int)_node.NodeTypeId);

childNode.Attributes.Add(

"NT", nodeLink.TMPNode.NodeTypeId.ToString());

result.Add(childNode);

}

node.ExpandMode =

TreeNodeExpandMode.WebService;

return result.ToArray();

}

[Plamen]

Hello Graham,

 
It looks like this behavior is by the session in the GetChildNodes() method. I am attaching a sample project based on our online demo where is shown show we recommend implementing the Web Service binding in RadTreeView.

Hope this will help you.

Regards,
Plamen Zdravkov
the Telerik team