Objective C: Cell text disappears after scrolling out of screen (and back) - objective-c

Question

I am creating a controller with a UITableview which contains 2 sections. In the second section, I have a list of users which I want to add a checkmark to the user in the list when I click on the particular row. I have an issue whereby after I click on a user and scroll the cell out of the page, the cell returns with the 'name' field BLANK (see screenshot below). I know this has to do with the way the cells are reused but am not able to get my head around the exact issue. My code is posted below. Any advise?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString* ShareOnCellIdentifier = #"ShareOnholderCell";
static NSString* WhoShouldAnswerCellIdentifier = #"WhoShouldAnswerCell";
int row = [indexPath row];
User *user = [self.friendsToShareWithArray objectAtIndex:row];
if (indexPath.section == 0)
{
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:ShareOnCellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ShareOnCellIdentifier];
}
cell.textLabel.text = [self.shareOnArray objectAtIndex:indexPath.row];
return cell;
}
else
{
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:WhoShouldAnswerCellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:WhoShouldAnswerCellIdentifier];
}
cell.textLabel.text = user.nickname;
if (user.isSelected)
{
cell.selectionStyle = UITableViewCellAccessoryCheckmark;
}
else
{
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
return cell;
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
User *user = [self.friendsToShareWithArray objectAtIndex:indexPath.row];
if (indexPath.section == 1)
{
UITableViewCell* cell = [tableView cellForRowAtIndexPath:indexPath];
if (cell.accessoryType == UITableViewCellAccessoryCheckmark)
{
cell.accessoryType = UITableViewCellAccessoryNone;
user.isSelected = NO;
}
else
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
user.isSelected = YES;
}
}
}
EDIT: Example of how I create my user object
User *user1 = [[User alloc]init];
user1.nickname = #"Dionis";
user1.uid = #"1";
user1.isSelected = NO;

Answer 1

The only problem I see is in the way you've implemented didSelectRowAtIndexPath: method.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.section == 1)
{
User *user = [self.friendsToShareWithArray objectAtIndex:indexPath.row];
user.isSelected = !user.isSelected;
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationNone];
}
}

Answer 2

I've had this kind of issue in the past caused by not realizing that basically every time a cell comes into view in a scrollable UITableView, it'll be re-requested via cellForRowAtIndexPath. I can't see an error being made here (you're always setting the label's text), but at this point I would suggest checking the text of the label after you set it.:
if (!cell.textLabel.text || [[cell.textLabel.text stringByReplacingOccurrencesOfString:#" " withString:#""] isEqualToString:#""])
NSAssert(NO, #"Bad text!");
Running in debug, this will "crash" at the NSAssert if the text is blank or nil. Then you might be able to inspect the surrounding variables (could user be nil, or something like that?) and find out more.