title: when and how to detect an iCloud conflict?
body: <p>I use iCloud to sync an user xml file between devices in my apps, with a UIDocument subclass, similar to the code from the question:http://stackoverflow.com/questions/7795629/icloud-basics-and-code-sample. but I am not sure when and how should I detect a conflict. I read the sdk doc and searched  the internet but didn't seem to find any information with detailed information. it seems we can use some code like
                  NSNumber* conflicted ;
                  [url getResourceValue:&amp;conflicted forKey:NSURLUbiquitousItemHasUnresolvedConflictsKey error:nil];</p>
  
  <p>but in my app, it seems always give a true value for "conflicted"?
  also I am not sure when should I detect the conflict, my guess is before the contentsForType method of the UIDocument subclass is called. if anyone can give any hint that would be great.</p>