Leaf/child nodes of a Tree Grid does not default to Folder Icon with a "+"

[vamsimp]

Hi,

I have a requirement to fetch the child records of a tree node on expanding it using the "+" sign of the folder. If any particular node doesnt have children the "+" sign should vanish. This requirement is similar to the one in below link.

http://www.smartclient.com/smartgwt/showcase/#tree_databinding_ondemand

But some how this doesn't work for me. Only parent show a folder and the child nodes do not default to a Folder. Below is the code I am using.
I have copied the code from the above link. The only change being replacing the data source with tree nodes.

public void onModuleLoad()
{
Tree adminTree = new Tree();
adminTree.setID("adminTreeId");
adminTree.setModelType(TreeModelType.PARENT);
adminTree.setRootValue("/");
adminTree.setAutoOpenRoot(true);

TreeGrid adminTreeGrid = new TreeGrid();
adminTreeGrid.setWidth(500);
adminTreeGrid.setHeight(400);
adminTreeGrid.setShowOpenIcons(false);
adminTreeGrid.setShowDropIcons(false);
//adminTreeGrid.setClosedIconSuffix("");
adminTreeGrid.setAutoFetchData(true);
adminTreeGrid.setData(adminTree);

TreeNode treeNode1 = new TreeNode();
treeNode1.setTitle("Node 1");
treeNode1.setID("node1");

TreeNode treeNode2 = new TreeNode();
treeNode2.setTitle("Node 2");
treeNode2.setID("node2");

TreeNode treeNode3 = new TreeNode();
treeNode3.setTitle("Node 3");
treeNode3.setID("node3");

TreeNode treeNode4 = new TreeNode();
treeNode4.setTitle("Node 4");
treeNode4.setID("node4");

adminTree.add(treeNode1, "/");
adminTree.add(treeNode2, "/");
adminTree.add(treeNode3, treeNode1);
adminTree.add(treeNode4, treeNode2);

adminTreeGrid.draw();
}

"Node 1" and "Node 2" are showing a folder with a "+" sign but "Node 3" and "Node 4" do not show give an option to expand them.

Please help out if I am missing something.

Thanks,
Vamsi

[davidj6]

Because you are specifying the tree nodes manually the treegrid knows there are no children so the [+] is not shown. If you use a datasource and loadondemand they will be there automatically. If you must provide nodes manually, look at the isFolder property so you can specify on each node the type.