How to populate, Expandable TableView with two NSMutableArray using objective-c

I think you need to create a TableView which will have a sections array, and each sections row will be populated using the corresponding sections array. Tapping on a section will expand it and it's all rows will be visible.

To meet your requirements, you could follow the below steps as well -

1) Your modal should have a array for sections. The sections array will contain the sections objects, name of the section and corresponding array of the rows.

2) Implement the data source methods of the table view like

- (NSInteger) numberOfSectionsInTableView:(UITableView *)tableView

{
    return [section count];
} 

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section

{
    return 50; // sections height
} 

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return nil;
}

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
    return nil;
}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{

    UIView *view = [[[UIView alloc] initWithFrame:CGRectMake(0 , 0, tableView.frame.size.width , 50)] autorelease];

    [view setBackgroundColor:[UIColor redColor]];
    view.layer.masksToBounds = YES;


    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(5 , 2 , view.frame.size.width - 10 , view.frame.size.height - 3)];
    label.text = ((SectionObject *)[section objectAtIndex:indexPath.section]).sectionName;
    label.backgroundColor = [UIColor clearColor];
    label.textAlignment = NSTextAlignmentLeft;
    label.textColor = [UIColor WwhiteColor];
    label.clipsToBounds = YES;
    label.font = [UIFont fontWithName:@"HelveticaNeue-CondensedBold" size:14.0f];
    label.layer.masksToBounds = YES;

    UIImageView *arrowImage = [[UIImageView alloc] initWithFrame:CGRectMake(view.frame.size.width - 30, 0, 17 , 17)];
    [arrowImage setCenter:CGPointMake(arrowImage.center.x , (view.frame.size.height/2) ) ];

    if(section == self.m_currentSelectedSection)
        [arrowImage setImage:self.m_upArrowImage];
    else
        [arrowImage setImage:self.m_downArrowImage];

    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, view.frame.size.width, view.frame.size.height)];
    button.tag = section;
    [button addTarget:self action:@selector(sectionTapped:) forControlEvents:UIControlEventTouchUpInside];
    button.backgroundColor = [UIColor clearColor];

    [view addSubview:label];
    [label release];

    [view addSubview:arrowImage];
    [arrowImage release];

    [view addSubview:button];
    [button release];

    view.clipsToBounds = YES;

    return view;
}



- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSInteger count = 0;

    if(self.m_currentSelectedSection == section)
              count = [((SectionObject *)[section objectAtIndex:indexPath.section]).rowArray count];

    return count;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 40.0;
}

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

    UITableViewCell *cell = nil;

    cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:cellId];

    if(cell == nil)
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
    }
    //customize cell
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:NO];
}

When ever any section will be tapped following event will be invoked

- (void) sectionTapped:(UIButton *)button
{
    self.m_currentSelectedSection = button.tag;
    [self performSelector:@selector(refreshView) withObject:nil afterDelay:POINT_ONE_SECOND];
    if(m_winnerSlotList->at(self.m_currentSelectedSection).m_leaderboardList.size())
        [self.m_leaderboardTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:button.tag] atScrollPosition:UITableViewScrollPositionTop animated:YES];

    UIView *baseView = [button superview];
    if(baseView)
    {
        for(int ii = 0 ; ii < [[baseView subviews] count] ; ii++ )
        {
            UIView *anyView = [[baseView subviews] objectAtIndex:ii];
            if([anyView isKindOfClass:[UIImageView class]])
                [(UIImageView *)anyView setImage:self.m_upArrowImage];
        }
    }
}

Initialize self.m_currentSelectedSection = 0, for the first time, this will show the rows for 0th section. As any section is tapped it's rows will be visible (corresponding section rows will expand) and the rows for the previous selected section will be hidden(previous section rows will collapse).

If you need to show more than one section as expanded than you need to keep track of all the section whether a section is expanded or not and accordingly load show/ hide the cells for the corresponding section.