title: Have Rails save valid attributes even if other attributes are invalid?
body: <p>I have a form that autosaves. I would like to be able to run validations and return error messages to the user, but I would also like to save all of the valid attributes. The frontend is angular so it would be a little annoying if you expected everything that is valid to save.</p>
  
  <p>I want to be able to do something like this:</p>
  
  <pre><code># @user = &lt;User name: "Chill Dude" favorite_color: "blue"&gt;
  @user.save(name: '', favorite_color: "red")
  @user.errors #=&gt; ["Name cannot be null"]
  @user.reload #=&gt; &lt;User name: "Chill Dude" favorite_color: "red"&gt;
  </code></pre>
  
  <p>I'm sure I could come up with some big complicated solution tapping in to <code>object.errors</code>, but I was wondering if there was any simple, rails-y way to do this?</p>