I would like to update my grid using datasourceurl, but allow local sorting that is maintained after the datasourceurl is updated.  Is this possible?

Here's a basic scenario of what I'd like to happen:

-Grid is initially loaded.

-User sorts grid by clicking on a column header.

-User selects a different option from some dropdown.

-Grid's data is updated, but the sorting of the column is retained.

Here's what I've tried so far:

client-side:

  var url = getNewUrlFromSomeDropDown();

  $myGrid.igGrid('option', 'dataSource', url);

...which causes that url to be hit, which does something like this (MVC / C#):

server:

Example 1 (doesn't work at all, grid is blank):

 public ActionResult _Employee_Grid(int someFilteringInt)

    {
      List<Employee> employees = GetEmployees(someFilteringInt);
 
      return Json(employees, JsonRequestBehavior.AllowGet);

    }

Example 2 (Populates grid with new data, but the data is not sorted in any particular way, and the sorting arrows are lost.)

public ActionResult _Employee_Grid(int someFilteringInt)
    {
      List<Employee> employees = GetEmployees(someFilteringInt);

      GridModel model = new GridModel();
      GridSorting sorting = new GridSorting();
      sorting.Mode = SortingMode.Single;
      model.Features.Add(sorting);
 
      model.DataSource = employees.AsQueryable<Employee>();
      return model.GetData();
    }

Also, in the 2nd example, I must add the sorting feature to the model, or else sorting is lost all together.  This means that the GetData() method generates different JSON data depending on the features and properties of the grid?  If so, this doesn't make sense IMO.  GetData should have nothing to do with the grid's setup.  It sort of defeats the purpose of only reloading the data instead of the entire grid.

Thanks in advance for any help!