title: Using NSKeyedArchiver to generate XML from NSManagedObjects held in an NSDictionary
body: <p>I have an NSDictionary, which contains a bunch of NSManagedObjects. 
  I can then use NSKeyedArchiver to write this to an NSData object.
  These are generated using <a href="https://gist.github.com/611157" rel="nofollow">this method.</a> Which works fine and allows me to save a section of schema to disc and then read it back as a new set of objects in the core data model.
  If I use either  archivedDataWithRootObject:
  or archiveRootObject:toFile:, as per the <a href="http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSKeyedArchiver_Class/Reference/Reference.html" rel="nofollow">documentation</a>
  I can see that the format of the archive is  NSPropertyListBinaryFormat_v1_0, whereas I want to serialise in NSPropertyListXMLFormat_v1_0, so that I can write my objects to a file and then process them elsewhere as plain old XML. (In fact I want to generate documents from them on a Windows based system.)</p>
  
  <p>1) Is there a way I can do this? If so how?
  2) Is there a better approach.</p>
  
  <p>I want to maintain the serialised nature, since I also want to send the file back to the iOS device later and recreate the object model.</p>