title: Rename xcdatamodel file
body: <p>What do in need to do to rename the .xcdatamodel file. Renaming .xcdatamodel filename, along with changing ...</p>
  
  <pre><code>NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"newfilename" withExtension:@"momd"];
  __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];    
  return __managedObjectModel;
  </code></pre>
  
  <p>and </p>
  
  <pre><code>NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"newfilename.sqlite"];
  </code></pre>
  
  <p>doesn't work! I get following error:</p>
  
  <pre><code>2011-04-11 17:19:54.164 ProjectName[5826:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Cannot create an NSPersistentStoreCoordinator with a nil model'
  *** Call stack at first throw:
  (
      0   CoreFoundation                      0x00fa15a9 __exceptionPreprocess + 185
      1   libobjc.A.dylib                     0x010f5313 objc_exception_throw + 44
      2   CoreData                            0x00013853 -[NSPersistentStoreCoordinator initWithManagedObjectModel:] + 419
      3   ProjectName                         0x00003471 -[ProjectNameAppDelegate persistentStoreCoordinator] + 257
      4   ProjectName                         0x000031a4 -[ProjectNameAppDelegate managedObjectContext] + 100
      5   ProjectName                         0x000028ca -[ProjectNameAppDelegate makeSplitViewController] + 762
      6   ProjectName                         0x00002d44 -[ProjectNameAppDelegate application:didFinishLaunchingWithOptions:] + 68
      7   UIKit                               0x001f3c89 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1163
      8   UIKit                               0x001f5d88 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 439
      9   UIKit                               0x00200617 -[UIApplication handleEvent:withNewEvent:] + 1533
      10  UIKit                               0x001f8abf -[UIApplication sendEvent:] + 71
      11  UIKit                               0x001fdf2e _UIApplicationHandleEvent + 7576
      12  GraphicsServices                    0x018f9992 PurpleEventCallback + 1550
      13  CoreFoundation                      0x00f82944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
      14  CoreFoundation                      0x00ee2cf7 __CFRunLoopDoSource1 + 215
      15  CoreFoundation                      0x00edff83 __CFRunLoopRun + 979
      16  CoreFoundation                      0x00edf840 CFRunLoopRunSpecific + 208
      17  CoreFoundation                      0x00edf761 CFRunLoopRunInMode + 97
      18  UIKit                               0x001f57d2 -[UIApplication _run] + 623
      19  UIKit                               0x00201c93 UIApplicationMain + 1160
      20  ProjectName                         0x00002599 main + 121
      21  ProjectName                         0x00002515 start + 53
  )
  terminate called after throwing an instance of 'NSException'
  </code></pre>
  
  <p>Note: I'm using Xcode4.</p>