title: Can you force activerecord associations to update without saving them?
body: <p>I have a couple models which are associated with the <code>has_many</code> <code>belongs_to</code> pair.  For the sake of demonstration, a client has one server but a server has many clients.  I might do something like this:</p>
  
  <pre><code>client1.server = the_server
  client2.server = the_server
  client3.server = the_server
  </code></pre>
  
  <p>My actual application is quite a bit more complex than this, but the example will work for illustration.</p>
  
  <p>I want to inspect the associations between these objects before I save them.  ActiveRecord doesn't update their information until they are saved though.  In the example above, <code>the_server</code> has no idea who <code>client1</code>, <code>client2</code>, or <code>client3</code> are until one of them gets saved.  I'm sure that this helps active_record's efficiency, but it leaves model instances in memory in an inconsistent state.</p>
  
  <p>Is there anything I can call on the clients or on the server that will cause them to update their states?</p>