iOS Application Terminates After Exception Thrown in UITableViewDataSource Method - iphone

Question

Having meticulously followed the examples and instructions in the Table View Programming Guide for iOS about the proper order in which UITableView delegate and data source methods are called, I thought I had a good idea of how to implement the “handshake” shown in Figure 7-1 and the list that follows, but apparently not.
Here's the code I'm using…
- (void) tableView: (UITableView *) tableView commitEditingStyle: (UITableViewCellEditingStyle) editingStyle forRowAtIndexPath: (NSIndexPath *) indexPath {
NSLog(#"Removing %# row %d.", [dataModel objectAtIndex: indexPath.row], indexPath.row);
[tableView deleteRowsAtIndexPaths: [NSArray arrayWithObjects: indexPath, nil] withRowAnimation: UITableViewRowAnimationFade];
[dataModel removeObjectAtIndex: indexPath.row];
}
tableView is the UITableView
dataModel is an NSArray instance that holds the objects represented by the UITableViewCells from the tableView.
…and the error I'm getting…
2010-08-27 21:53:17.971 SportWatch[1299:307] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit/UIKit-1262.58/UITableView.m:920
2010-08-27 21:53:17.992 SportWatch[1299:307] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (4) must be equal to the number of rows contained in that section before the update (4), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted).'
*** Call stack at first throw:
(
0 CoreFoundation 0x35411ed3 __exceptionPreprocess + 114
1 libobjc.A.dylib 0x311f0811 objc_exception_throw + 24
2 CoreFoundation 0x35411d15 +[NSException raise:format:arguments:] + 68
3 Foundation 0x332b932f -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 62
4 UIKit 0x338dcda1 -[UITableView(_UITableViewPrivate) _endCellAnimationsWithContext:] + 4524
5 UIKit 0x338d586d -[UITableView _updateRowsAtIndexPaths:updateAction:withRowAnimation:] + 204
6 UIKit 0x338d5775 -[UITableView deleteRowsAtIndexPaths:withRowAnimation:] + 20
7 SportWatch 0x000060e7 -[MainViewController tableView:commitEditingStyle:forRowAtIndexPath:] + 670
8 UIKit 0x338d3c3f -[UITableView(UITableViewInternal) animateDeletionOfRowWithCell:] + 58
9 UIKit 0x33984071 -[UITableViewCell(UITableViewCellInternal) deleteConfirmationControlWasClicked:] + 28
10 CoreFoundation 0x353b9719 -[NSObject(NSObject) performSelector:withObject:withObject:] + 24
11 UIKit 0x33831d59 -[UIApplication sendAction:to:from:forEvent:] + 84
12 UIKit 0x33831cf9 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 32
13 UIKit 0x33831ccb -[UIControl sendAction:to:forEvent:] + 38
14 UIKit 0x33831a1d -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 356
15 UIKit 0x3383206b -[UIControl touchesEnded:withEvent:] + 342
16 UIKit 0x338309f5 -[UIWindow _sendTouchesForEvent:] + 368
17 UIKit 0x3383036f -[UIWindow sendEvent:] + 262
18 UIKit 0x3382ae13 -[UIApplication sendEvent:] + 298
19 UIKit 0x3382a74b _UIApplicationHandleEvent + 5110
20 GraphicsServices 0x3171a04b PurpleEventCallback + 666
21 CoreFoundation 0x353a6ce3 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 26
22 CoreFoundation 0x353a6ca7 __CFRunLoopDoSource1 + 166
23 CoreFoundation 0x3539956d __CFRunLoopRun + 520
24 CoreFoundation 0x35399277 CFRunLoopRunSpecific + 230
25 CoreFoundation 0x3539917f CFRunLoopRunInMode + 58
26 GraphicsServices 0x317195f3 GSEventRunModal + 114
27 GraphicsServices 0x3171969f GSEventRun + 62
28 UIKit 0x337d148b -[UIApplication _run] + 402
29 UIKit 0x337cf69f UIApplicationMain + 670
30 SportWatch 0x00002b23 main + 70
31 SportWatch 0x00002ad8 start + 40
)
terminate called after throwing an instance of 'NSException'
Program received signal: “SIGABRT”.
kill
Current language: auto; currently objective-c
quit

Answer 1

remove the object from the data set before deleting the row.