Question

I want to make a GET action that only runs if it is called by another action, so not if the user types the URL in the address bar. What can I check to determine whether this is the case?

Answer 1

You may decorate the action with the ChildActionOnlyAttribute.

  [ChildActionOnly]
  public ActionResult Menu() {
    var menu = GetMenuFromSomewhere();
      return PartialView(menu);
  }

You may then use the RenderAction() and Action() Html helpers as usual and the action cannot be called by URL.

These are new to MVC 2, but from the tags I assume that you are already using that.

Sample: http://haacked.com/archive/2009/11/18/aspnetmvc2-render-action.aspx