title: Updating value provider prior to TryUpdateModel
body: <p>Lets say we have a class with a property called PetsName. If it is left blank on the screen I want to update the value provider so if the user doesn't enter a pet name, we force 'unnamed'. This isn't the actual scenario.. this is of course a sample, so answers like 'just set default values on a webpage, etc' won't fit this scenario  : )</p>
  
  <p>The main issue is we want to update the values so when you update the model it will use whatever you have overridden. I guess one idea is to remove the value and add it. When I check ModelState, it does have the updated value, however when I call TryUpdateModel, the value is not updated. Its possible what Im doing below is indeed correct and there is another issue here but I figured I'd try this first. Thanks!</p>
  
  <p><code></p>
  
  <pre><code>    //Sample case:
  
      [HttpPost]
      public ActionResult Edit(PetOwner petOwner)
      {
  
      //If pets name is not set, force to "Unknown"
      if(petOwner.PetsName=="")
      {
      //Tried this too ModelState.Remove("PetsName");
      //ModelState.Add("PetsName", new ModelState());
      ModelState["PetsName"].Value = new ValueProviderResult("Unnamed", "Unnamed", CultureInfo.CurrentCulture);
      }
  
      //Get the record/relationships from DB to merge with ModelState
      PetOwner petOwnerToSave = from o in ctx.PetOwners where o.PetOwnerId == petOwner.PetOwnerId select o;
  
      TryUpdateModel(petOwnerToSave);
  
      //Save petOwnerToSave
      }
  </code></pre>
  
  <p></code></p>