[Solved] How do I expand all parent nodes of the selected node

[Alastair Eddie]

Hi,

I'm persiting treeview state in a cookie.

Rather than store the expanded/collapsed state for every node, I'd rather just store the currently selected node. My controller then passes the SelectedNode to the view containing the tree and the item is set as follows...

item.Selected = ((string)ViewData["SelectedNode"] == item.Value);

My question is, how can I get the treeview to expand all the parent nodes of an item that I set as Selected during the bind?

Thanks,
Alastair Eddie

[Georgi Krustev]

Hello Alastair,

You can try this approach:

<asp:content contentplaceholderid="MainContent" runat="server">

<script runat="server">
    public void Expander(TreeViewItem item)
    {
        if(item.Parent != null)
        {
            item.Expanded = true;
            Expander(item.Parent);
        }
    }
</script>

<%= Html.Telerik().TreeView()
        .Name("TreeView")
        .BindTo(Model, mappings =>
        {
            mappings.For<Category>(binding => binding
                    .ItemDataBound((item, category) =>
                    {
                        item.Text = category.CategoryName;
                    })
                    .Children(category => category.Products));

            mappings.For<Product>(binding => binding
                    .ItemDataBound((item, product) =>
                    {
                        item.Text = product.ProductName;
                        Expander(item);
                    }));
        })
%>

</asp:content>

Look at the Expander method. You can use it in order to achieve your goal.

Greetings,
Georgi Krustev
the Telerik team

[Alastair Eddie]

Bravo - works a treat.

Thanks,
Alastair