title: MVC Partial Model Updates
body: <p>I often find myself in the situation where I only want to present and edit some fields from my model. Let's say I have a model that represts an address, perhaps I just want the form to update the city and post code fields (bad example, but hopefully it explains the scenario).</p>
  
  <p>I know of two methods:</p>
  
  <p>1) Persist the unwanted fields in hidden input elements on the form, or...
  2) Create a dedicated view model that just defines the fields I need.</p>
  
  <p>I favour option #2, but I don't have a nice clean way of merging the data from the view model back into the 'real' model within the controller action.  At the moment, I follow this approach...</p>
  
  <p>1) Store the record I'd in a hidden field on the view model
  2) When the page posts back, the controller retrieves the original record and I manually assign each field from the view model to the real model
  3) Save the real model back to the data store.</p>
  
  <p>This works, but it is quite a lot of work and very easy to miss an assignment/reassignment and I was wondering if anyone knew of another approach?</p>