[Solved] Setting visible=false can display incorrectly

[Darren Hall]

I have a treeview that shows nodes according to a users role.  if the user is not in the correct role I set visible = false on the node they should not see.  However if a node has several children and all children are set to visible = false, the actual rendered HTML still includes an empty <UL> where they would have been.  This causes a gap in the display.

I have come up with a workaround for anyone experiencing the same problem. You need to hook the treeview pre render as follows;

    protected void RadTreeView1_PreRender(object sender, EventArgs e)
    {
        // Note that although we set nodes that should not be displayed to visible = false
        // Telerik still displays the <UL> for an empty section, we have to actually remove the nodes
        // from the collection in order to display correctly.
        // We use GetAllNodes for this as it returns every node in the tree and we count backwards
        // so as not to upset the collection when items are removed.
        for (int i = ((RadTreeView)sender).GetAllNodes().Count - 1; i >= 0 ; i--)
        {
            if (((RadTreeView)sender).GetAllNodes()[i].Visible == false)
            {
                ((RadTreeView)sender).GetAllNodes()[i].Remove();
            }
        }
    }

This removes the nodes from the collection and displays correctly.

Darren