TreeView / Performance with Web Services

1. Use Web Service load on demand.

   Web Service load on demand does not request the page and avoids the execution of the page life cycle. Less data is transferred between the client and the server.

2. Set the PersistLoadOnDemandNodes property to false.

   Persistence of nodes loaded on demand is enabled by default. This is required if you need load on demand nodes to trigger server side events (NodeClick, NodeDrop). If you don't consume the NodeClick or NodeDrop events you can disable the persistence of nodes loaded on demand to improve the performance.

3. The EnableViewState property is set to false.

   ViewState is not required if PersistLoadOnDemandNodes is set to false. Disabling it would save some output.

4. The implementation of the Web Service methods uses two optimization techniques to decrease the size of the generated JSON output:
   • The return type of the web method is IEnumerable. This prevents the serialization of the type name in the JSON output:

     [WebMethod]
     public IEnumerable GetNodes(RadTreeNodeData node, IDictionary context) 
     {
         int numberOfNodes = 1000;
         List<NodeData> nodes = new List<NodeData>();
         for (int i = 0; i < numberOfNodes; i++)
         {
             NodeData nodeData = new NodeData();
             nodeData.Text = "Node " + i;
             nodes.Add(nodeData);
         }
     
         return nodes;
     }
     				

   • The web method returns only the data required by the application. In this case only the node's Text property is serialized by using a custom class - NodeData. You should prefer this approach over using the RadTreeNodeData class to preserve output size:

     class NodeData
     {
         private string text;
     
         public string Text
         {
             get { return text; }
             set { text = value; }
         }
     }
     				

The OnClientNodePopulating and OnClientNodePopulated events are used only to measure the time requred to perform the load on demand operation. Consuming them is not required for the proper operation of RadTreeView in this scenario.
Consuming the OnClientNodeClicked event is used to trigger server side event when the user clicks a node.