CODEWITHSUNDEEP
iphoneobjective-cxcodeuitableview
Korg
Korg

Reputation: 41

Insert new row in UITableView when tapping first row

I'm new to iOS development. Therefore it would be nice if your answer could be as detailed as possible. My problem is the following: I want the cell in my second section to always say "add new row". If you click this cell a new row should be added on top. My current code is

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{

// Return the number of sections.
return 2;
 }
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

// Return the number of rows in the section.
if (section == 0) {
    return 1;
}
else {

    return [entries count];
}
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath        *)indexPath
{
static NSString *simpleTableIdentifier = @"Cell";
static NSString *todayTableIdentifier = @"Notification";
UITableViewCell *cell = [tableView       dequeueReusableCellWithIdentifier:simpleTableIdentifier];
UITableViewCell *todaycell = [tableView dequeueReusableCellWithIdentifier:todayTableIdentifier];

if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];


}
NSString *entry;
if (indexPath.section == 0) {
    entry = [notifications objectAtIndex:indexPath.row];
    cell = todaycell;
} else {
    entry = [entries objectAtIndex:indexPath.row];
}
cell.textLabel.text = entry;

return cell;

}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

int selectedRow = indexPath.row;
NSLog(@"row pressed %d", selectedRow);
NSArray *paths = [NSArray arrayWithObject:
                  [NSIndexPath indexPathForRow:2 inSection:2]];
if (selectedRow == 0)
{   [entries addObject:@"a new Entry"];
    [[self tableView] insertRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];
}
else {
    [[self tableView] deleteRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];
  }
}

Unfortunately, my app keeps crashing.

2013-04-11 16:52:39.717 MyStore[12924:c07] *** Assertion failure in -[UITableView    _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-2380.17/UITableView.m:861
2013-04-11 16:52:39.718 MyStore[12924:c07] *** Terminating app due to uncaught exception '    NSInternalInconsistencyException', reason: 'attempt to delete row 2 from section 2, but there    are only 2 sections before the update'
*** First throw call stack:
(0x1faa012 0x13e7e7e 0x1fa9e78 0xb6d665 0xbb43c 0xca1f6 0xca271 0x5c6b 0xcb285 0xcb4ed    0xad55b3 0x1f69376 0x1f68e06 0x1f50a82 0x1f4ff44 0x1f4fe1b 0x1f047e3 0x1f04668 0x1bffc 0x21bd  0x20e5 0x1)
libc++abi.dylib: terminate called throwing an exception

Upvotes: 1

Views: 14138

Answers (1)

Rui Peres
Rui Peres

Reputation: 25917

That's normal, besides adding a new row (visually), you need to update your Data Source (the notifications array in this case). The UI is just the visualization of your Data Source. So:

[notifications addObject:@"a new Entry"];

[[self tableView] insertRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];

And when you delete:

 [notifications removeObjectAtIndex:indexPath.row];

 [[self tableView] deleteRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];

Upvotes: 5

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