iOS - how to set a checkmark in a UITableView the first time the table is loaded

Question

I am an iOS newbie. I am using a checkmark to in a UITableView, and storing the checked value in a local database. When I load the app for the first time, I want to set the value of the checkmark depending on which value exists in the db. How would I do that? Presently this is what I do -

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
if ([indexPath compare:self.lastIndexPath] == NSOrderedSame) 
{
    cell.accessoryType = UITableViewCellAccessoryCheckmark;
} 
else 
{
    cell.accessoryType = UITableViewCellAccessoryNone;
}
// Set up the cell...
NSString *cellValue = [[self countryNames] objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;

return cell;
}

and then in didSelectRowAtIndexPath -

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

// some stuff
self.lastIndexPath = indexPath;
[tableView reloadData];
}

score 3 · Accepted Answer · edited Jul 12 '12 at 07:45

Are you asking simply how and when to set the checkmark or are you asking how to populate a table from a database (eg Core Data)?

From your code, the only data you represent is in [self countryNames] and it's not clear under what circumstances you'd want the cell to display a checkmark. Whatever that is, just check the condition and set the checkmark when you are configuring your cell for data (after your "Set up the cell..." comment).

Example if you stored the users country and checked that cell:

// get the current country name
NSString *cellValue = [[self countryNames] objectAtIndex:indexPath.row];

// configure the cell
cell.textLLabel.text = cellValue;
UITableViewCellAccessoryType accessory = UITableViewCellAccessoryNone;
if ([cellValue isEqualToString:self.usersCountry]) {
    accessory = UITableViewCellAccessoryCheckmark;
}
cell.accessoryType = accessory;

score 0 · Answer 2 · answered Nov 07 '11 at 23:23

If you have static table data, then you simply need to store the section and row of the selected table view cell. If you have dynamic data, then you will need to store the unique data for that selected cell in the database and compare that with the cell's content on load. When you are loading your cells in cellForRowAtIndexPath:, simply set that cell's accessory to UITableViewCellAccessoryCheckmark as well as set self.lastIndexPath = indexPath for comparison later.

Also, I typically use [indexPath isEqual:self.lastIndexPath] instead of compare:. Doesn't really make a difference either way, just for readability.

iOS - how to set a checkmark in a UITableView the first time the table is loaded

2 Answers2