title: Laravel Eloquent Model Attributes
body: <p>After instantiating a model class that extends Laravel's Eloquent Model class, is there a way to determine if the property/attribute maps to the table, and therefore can be saved to the table?</p>
  
  <p>For example, I have a table <code>announcements</code> with columns <code>id</code>, <code>text</code> and "created_by".</p>
  
  <p>How can I know <code>created_by</code> is an attribute and will be saved if set?</p>
  
  <pre><code>$announcement = new Announcement();
  </code></pre>
  
  <p><code>isset($announcement-&gt;created_by)</code> understandably returns false if I haven't explicitly set the value yet. I have tried various functions inherited from the Eloquent model class, but so far none have worked. I'm looking for something like:</p>
  
  <p><code>$announcement-&gt;doesThisMapToMyTable('created_by')</code> that returns true whether or not <code>$announcement-&gt;created_by</code> has been set.</p>