title: Subclass for Superclass with @dynamic @properties
body: <p>I'm using <a href="https://github.com/dhennessy/PAPreferences" rel="nofollow">PAPreferences</a> to manage app specific preferences/defaults. It's basically a layer on top of <code>NSUserDefaults</code> that lets me read/write data to NSUserDefaults as if I was just using a normal class.</p>
  
  <p>The basic setup is to subclass PAPreferences, add <code>@properties</code> in your subclass' .h file, <strong>and declare them as <code>@dynamic</code> in the .m file</strong>.</p>
  
  <p>The class hierarchy looks like this:</p>
  
  <pre><code>- PAPreferences
      - MyPreferences // all @properties defined here, and set in -init
  </code></pre>
  
  <p>My project builds many different targets, and each time I add a new target, I have to duplicate the previous <code>MyPreferences</code> file. A lot of code is duplicated, and each time I want to make a change to my app's preferences, I have to do so in many different files.</p>
  
  <p>I'd like to create a class hierarchy like so:</p>
  
  <pre><code>- PAPreferences
      - MyPreferencesBase // all @properties defined here
          - MyPreferences // all @properties set in -init
  </code></pre>
  
  <p>With the previous class hierarchy, my app is crashing when <code>MyPreferenes#init</code> is run and I set the first instance variable  (unrecognized selector sent to instance).</p>
  
  <p>How can I write a subclass for a superclass whose @properties are set to be @dyanmic?</p>