loadOnDemand Boolean (default: true)

Indicates whether the child DataSources should be fetched lazily when parent groups get expanded. Setting this to false causes all child DataSources to be loaded at initialization time.

Note: when initializing the widget from an array (rather than from a HierarchicalDataSource instance), this option defaults to false, rather than true.

Example - force lazy loading of sublevels

<div id="treeview"></div>
<script>
  var serviceRoot = "https://demos.telerik.com/kendo-ui/service";
  homogeneous = new kendo.data.HierarchicalDataSource({
    transport: {
      read: {
        url: serviceRoot + "/Employees",
        dataType: "jsonp"
      }
    },
    schema: {
      model: {
        id: "EmployeeId",
        hasChildren: "HasEmployees"
      }
    }
  });

  $("#treeview").kendoTreeView({
    dataSource: homogeneous,
    loadOnDemand: false,
    dataTextField: "FullName"
  });
</script>