title: Using Automapper.TypeMap to map a Property by name
body: <p>I am using <code>AutoMapper</code> to map my MVC <code>ViewModels</code> to a <code>DTO</code> and back again, and was wondering if it was possible to utilize a <code>TypeMap</code> from <code>AutoMapper</code> to map a value via only a property name?</p>
  
  <p>My scenario is this:</p>
  
  <ol>
  <li>I map a <code>ViewModel</code> to a <code>DTO</code> via Automapper.</li>
  <li>I send the <code>DTO</code> over a WCF call, which fails validation.</li>
  <li>I get a <code>FaultException</code> back with the name of the <code>DTO</code> field that failed.</li>
  <li>I need to set <code>ModelState</code> dictionary with the name of the <code>ViewModel</code> property that failed, and the error message. This allows me to highlight the errored field on the screen.</li>
  </ol>
  
  <p>So my issue lies in being able to map the <code>string</code> name of the <code>DTO</code> property that failed, back to the <code>ViewModel</code> property. I would like to do something like this:</p>
  
  <pre><code>var typemap = Mapper.FindTypeMapFor(typeof(DTO), typeof(Model))
  string erroredPropertyName = "Prop1"; // Really extracted from my Fault
  
  // This is the bit that doesn't exist, and I need help with......
  //  string destination = typemap.GetDestinationFor(erroredPropertyName);
  
  ModelState.Add(destination, errorMessage);
  </code></pre>
  
  <p>Is this at all possible? I don't mind using <code>Reflection</code> if I have to, but would prefer not to use it if I can.</p>