didSelectRowAtIndexPath with section

Question

I have a UITableView which I have assigned sections. When using didSelectRowAtIndex with indexPath.row I am not getting the correct value. Let's say I'm in section 2, then it starts the row index at 0 again and therefore I am getting the wrong index.

Can anyone tell me how to fix this? I realize that it is possible to get the section index by indexPath.section but I can't figure out how to use this.

bandDetailViewController.band = [self.programArray objectAtIndex:indexPath.row];

I hope you can help me. Thanks in advance :-)

EDIT:

Sample data. My cells for the table view is loaded from this plist.

<array>
    <dict>
        <key>name</key>
        <string>Alphabeat</string>
        <key>description</key>
        <string>Long description.</string>
        <key>scene</key>
        <string>Store Scene</string>
        <key>date</key>
        <date>2011-02-04T20:09:40Z</date>
        <key>hasDate</key>
        <true/>
        <key>weekDay</key>
        <string>Onsdag</string>
        <key>youtubeVideo</key>
        <string>http://www.youtube.com/watch?v=dB01PTZNpBc</string>
    </dict>
    <dict>
        <key>name</key>
        <string>Anne Linnet</string>
        <key>description</key>
        <string>Long description.</string>
        <key>scene</key>
        <string>Store Scene</string>
        <key>date</key>
        <date>2011-02-04T20:09:40Z</date>
        <key>hasDate</key>
        <true/>
        <key>weekDay</key>
        <string>Onsdag</string>
        <key>youtubeVideo</key>
        <string>http://www.youtube.com/watch?v=jWMSqS7fL9k</string>
    </dict>
</array>

Answer 1

I just came across this issue as well. I found a simple solution using the section number as you mentioned The following code uses segues to navigate to new controlView from two different sections with two different rows. VERY simple solution!

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


if (indexPath.section == 0)
{


    switch(indexPath.row) {
        case 0:
            [self performSegueWithIdentifier:@"Mission" sender:self];
            break;
        case 1:
            //[self performSegueWithIdentifier:@"Music" sender:self];
            break;

     }
}else{

    switch(indexPath.row) {
        case 0:
            [self performSegueWithIdentifier:@"Contact" sender:self];
            break;
        case 1:
            //[self performSegueWithIdentifier:@"Home" sender:self];
            break;
    }


}

}

Answer 2

The rows are not consecutive and start from scratch in each section:

section 0:
row 0
row 1
row 2
row ...

section 1:
row 0
row 1
row 2
row ...

...

The best way is to build an NSMutableArray sections with NSMutableArrays for the rows. Than you code gets very easy:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return cellSections.count;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    CellSection *cellSection = [cellSections objectAtIndex:section];
    return cellSection.cellElements.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSString *cellIdentifier = [NSString stringWithFormat:@"Cell-%i-%i", indexPath.section, indexPath.row];

    CellSection *cellSection = [cellSections objectAtIndex:indexPath.section];
    CellElement *cellElement = [cellSection.cellElements objectAtIndex:indexPath.row];

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];

        [cell.contentView addSubview:cellElement.contentView];

    }


    return cell;

}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    CellSection *cellSection = [cellSections objectAtIndex:indexPath.section];
    CellElement *cellElement = [cellSection.cellElements objectAtIndex:indexPath.row];

}

---

EDIT:

Just an example:

@interface CellSection : NSObject {

}

@property (nonatomic, retain) NSMutableArray *cellElements;
@property (nonatomic, retain) NSString *headerString;
@property (nonatomic, retain) UIView *headerView;

@end

---

@interface CellElement : NSObject {

}

@property (nonatomic, retain) UIView *contentView;
@property BOOL isSelectable;
@property BOOL hasAccessoryIndicator;
@property SEL action;

@end

Answer 3

I have had the same problem and I have solved it this way:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *selected = [_products objectAtIndex:[self getRealIndexFromIndexPath:indexPath]];
NSLog(@"%@", selected);

}

- (NSUInteger)getRealIndexFromIndexPath:(NSIndexPath*)indexPath {   
NSUInteger temp = 0;
for (int i = 0; i < indexPath.section ; i++) {
    temp += [_mySectionedTable numberOfRowsInSection:i];
}
return temp + indexPath.row;

}

Hope it helps :-) Cheers!

Answer 4

If I follow you correctly, you could try

NSUInteger index = indexPath.row * (indexPath.section + 1);
bandDetailViewController.band = [self.programArray objectAtIndex:index];

Or something like that. More typically you'll have an array of objects that represent your sections, and each of those section objects will have its own array representing its rows.

Answer 5

If you implemented

tableview cellForRowAtIndexPath

then in the didSelectRowAtIndexPath you can call this method to retrieve the value selected. No need to rearrange your data structures if it is too hard. Its what I ended up doing with the variable length sections and works great.

NSString *selectedValue = [self tableView:theTableView cellForRowAtIndexPath:indexPath].textLabel.text;

Answer 6

The usual approach to dealing with variable-length sections (which I'm assuming is the case here) is to create a collection that represents the sections containing nested collections to represent the rows. So for example you could have a top-level NSMutableArray of section values, where each element is an NSMutableArray of row values.

EDIT

Given the current structure of your plist data, another approach would be to filter the array using an instance of NSPredicate. For example, the following code would filter the rows for the current section based on days of the week:

static NSArray *days;

if (days == nil)
{
    // Populate the array with days of the week in the order 
    // in which you want the table view to present the sections.
    days = [NSArray arrayWithObjects:@"Monday", @"Tuesday", nil];
}

NSString *day = [days objectAtIndex:[indexPath section]];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"weekDay like %@", day];
NSArray *filteredDicts = [[self programArray] filteredArrayUsingPredicate:predicate];

Note that you'd also need to modify tableView:numberOfRowsInSection: to use the same mechanism so that it would return the correct number of rows for each section.

Answer 7

If you look at the NSIndexPath documentation, you can see how the NSIndexPath data structure is laid out.

To get the section number you want to do something like:

[indexPath indexAtPosition:0]

To get the row within that section:

[indexPath indexAtPosition:1]