Magical Record, delete from UITableView “invalid number of rows in section 0…”

Question

I'm using Magical Record to manage my CoreData . When user delete specific cell in the table, what I do is:

Set flag and delete the row from table:

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView beginUpdates];

    if (editingStyle == UITableViewCellEditingStyleDelete) {
        MessageTableViewCell *cell = (MessageTableViewCell *)[tableView cellForRowAtIndexPath:indexPath];

        NSArray *sortedMessageID = [cell.photoDetails.message.message_id componentsSeparatedByString:@"_"];
        NSString *messageID = sortedMessageID[1];

        NSLog(@"cell.photoDetails.message.message_id: %@", cell.photoDetails.message.message_id);
        NSLog(@"sortedMessageID: %@", sortedMessageID);

        NSAssert(sortedMessageID[1] != nil, @"sortedMessageID[1] cannot be nil.");
        NSAssert(messageID != nil, @"messageID cannot be nil.");

        if (cell.photoDetails) {
            [MagicalRecord saveWithBlockAndWait:^(NSManagedObjectContext *localContext) {
                cell.photoDetails.message.delete_message = @YES;
            }];
        }

//        [self.dataSource removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];

        [self performSelectorInBackground:@selector(deleteMessagesFromServer:) withObject:messageID];
    }

    [tableView endUpdates];
}

Update the server which IDs to delete, server send back the IDs and if they match, I delete them from CoreData:

@try {
        TreeNode *root = [TreeNode treeNode];
        XMLParser *parser = [[XMLParser alloc] init];
        root = [parser parseXMLFromData:data];

        if (root.key && [root.key.lowercaseString isEqualToString:@"messages"]) {
            for (TreeNode *children in root.children) {
                if ([children.key.lowercaseString isEqualToString:@"message"]) {

                    for (TreeNode *children2 in children.children) {
                        if ([children2.key isEqualToString:@"id"]) {
                            NSPredicate *predicate = [NSPredicate predicateWithFormat:@"message.message_id ==[c] %@", children2.leafvalue];

                            BOOL isDelete =  [CoreDataPhotoRecord MR_deleteAllMatchingPredicate:predicate];
                            [[NSManagedObjectContext MR_defaultContext] MR_saveOnlySelfAndWait];
                            NSLog(@"%s, isDelete: %@", __PRETTY_FUNCTION__, @(isDelete));
                        }
                    }
                }
            }

            NSLog(@"allAcceptedRecords.count: %lu", (unsigned long)[HumanResponse allAcceptedRecords].count);
            //            NSLog(@"allAcceptedRecords.count: %lu, self.dataSource.count: %lu",
            //                  (unsigned long)[HumanResponse allAcceptedRecords].count, (unsigned long)self.dataSource.count);
        }
    }
    @catch (NSException *exception) {
        NSLog(@"%s, exception.reason: %@", __PRETTY_FUNCTION__, exception.reason);
    }

Additional code:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
//    return self.dataSource.count;
    return [HumanResponse allAcceptedRecords].count;
}

+ (NSArray *)allAcceptedRecords
{
    return [CoreDataPhotoRecord MR_findAllSortedBy:@"message.originalDate"
                                         ascending:NO
                                     withPredicate:[NSPredicate predicateWithFormat:@"message.delete_message == %@", @NO]];
}

Edit - 1:

Log is provided:

2014-10-23 11:12:07.140 Human Response[426:94571] tableView.isEditing: 1
2014-10-23 11:12:07.140 Human Response[426:94571] cell.photoDetails.message.message_id: m_1000075
2014-10-23 11:12:07.141 Human Response[426:94571] sortedMessageID: (
    m,
    1000075
)
2014-10-23 11:12:07.144 Human Response[426:94756] deleteMessages: userID=3&ids=1000075&mobile=0543111797
2014-10-23 11:12:07.144 Human Response[426:94571] -[MainTableViewController tableView:numberOfRowsInSection:], count: 12
2014-10-23 11:12:07.145 Human Response[426:94571] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit/UIKit-3318.16.14/UITableView.m:1582
2014-10-23 11:12:07.146 Human Response[426:94571] CRASH:
Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (12) must be equal to the number of rows contained in that section before the update (12), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).
2014-10-23 11:12:07.158 Human Response[426:94571] Stack Trace:
(
    0   CoreFoundation                      0x277a2c37 <redacted> + 150
    1   libobjc.A.dylib                     0x34f4dc8b objc_exception_throw + 38
    2   CoreFoundation                      0x277a2af5 <redacted> + 0
    3   Foundation                          0x28472d7f <redacted> + 90
    4   UIKit                               0x2ae2c7ef <redacted> + 8150
    5   Human Response                      0x000cd823 -[MainTableViewController tableView:commitEditingStyle:forRowAtIndexPath:] + 1802
    6   UIKit                               0x2ae445e3 <redacted> + 142
    7   UIKit                               0x2af1e025 <redacted> + 68
    8   UIKit                               0x2ac92c2b <redacted> + 70
    9   UIKit                               0x2ac92bd1 <redacted> + 44
    10  UIKit                               0x2ac7d863 <redacted> + 582
    11  UIKit                               0x2ac9263d <redacted> + 588
    12  UIKit                               0x2ac5742d <redacted> + 10268
    13  UIKit                               0x2ac8c2f1 <redacted> + 784
    14  UIKit                               0x2ac8bbcd <redacted> + 524
    15  UIKit                               0x2ac623dd <redacted> + 196
    16  UIKit                               0x2aed5c29 <redacted> + 13888
    17  UIKit                               0x2ac60e39 <redacted> + 1296
    18  CoreFoundation                      0x27769377 <redacted> + 14
    19  CoreFoundation                      0x27768787 <redacted> + 218
    20  CoreFoundation                      0x27766ded <redacted> + 772
    21  CoreFoundation                      0x276b5211 CFRunLoopRunSpecific + 476
    22  CoreFoundation                      0x276b5023 CFRunLoopRunInMode + 106
    23  GraphicsServices                    0x2eaae0a9 GSEventRunModal + 136
    24  UIKit                               0x2acc11d1 UIApplicationMain + 1440
    25  Human Response                      0x000bfc41 main + 116
    26  libdyld.dylib                       0x354cdaaf <redacted> + 2
)
2014-10-23 11:12:07.161 Human Response[426:94571] *** 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 (12) must be equal to the number of rows contained in that section before the update (12), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
*** First throw call stack:
(0x277a2c1f 0x34f4dc8b 0x277a2af5 0x28472d7f 0x2ae2c7ef 0xcd823 0x2ae445e3 0x2af1e025 0x2ac92c2b 0x2ac92bd1 0x2ac7d863 0x2ac9263d 0x2ac5742d 0x2ac8c2f1 0x2ac8bbcd 0x2ac623dd 0x2aed5c29 0x2ac60e39 0x27769377 0x27768787 0x27766ded 0x276b5211 0x276b5023 0x2eaae0a9 0x2acc11d1 0xbfc41 0x354cdaaf)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

What am I doing wrong?

Answer 1

As Sebastian Wramba suggested, I changed the way I'ms aving the context:

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView beginUpdates];

    if (editingStyle == UITableViewCellEditingStyleDelete) {
        NSLog(@"tableView.isEditing: %@", @(tableView.isEditing));

        MessageTableViewCell *cell = (MessageTableViewCell *)[tableView cellForRowAtIndexPath:indexPath];

        NSArray *sortedMessageID = [cell.photoDetails.message.message_id componentsSeparatedByString:@"_"];
        NSString *messageID = sortedMessageID[1];

        NSLog(@"cell.photoDetails.message.message_id: %@", cell.photoDetails.message.message_id);
        NSLog(@"sortedMessageID: %@", sortedMessageID);

        NSAssert(sortedMessageID[1] != nil, @"sortedMessageID[1] cannot be nil.");
        NSAssert(messageID != nil, @"messageID cannot be nil.");


        if (cell.photoDetails) {
            cell.photoDetails.message.delete_message = @YES;
            [self saveContext];

//            [MagicalRecord saveWithBlockAndWait:^(NSManagedObjectContext *localContext) {
//                cell.photoDetails.message.delete_message = @YES;
//            }];
        }

//        [self.dataSource removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];

        [self performSelectorInBackground:@selector(deleteMessagesFromServer:) withObject:messageID];
    }

    [tableView endUpdates];
}

#pragma mark - Magical Records

- (void)saveContext
{
    [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];
}