title: NSManagedObjectContext and NSArrayController reset/refresh problem
body: <p>I'm having trouble getting my UI to reflect external changes (made by another process) to an sqlite data store.</p>
  
  <p>I have a fairly standard core data based NSArrayController / table view. My app gets notified that external changes have been made to the data, at which point I do a</p>
  
  <pre><code>[managedObjectContext reset]; // brute force, but data set is small
  </code></pre>
  
  <p>The problem is, doing this clears all data from the table. The array controller's arrangedObjects is also empty. I thought a subsequent</p>
  
  <pre><code>[arrayController fetch:nil];
  </code></pre>
  
  <p>might help, but it doesn't. Executing a fetch request on the managedObjectContext shows the data is present and updated, so the managedObjectContext knows about the changes.</p>
  
  <p>Any clues as to how to "recover" from the reset? Or perhaps the reset approach is wrong altogether, in which case is there a better way to load the external changes?</p>