Sort UITableView into sections by date from Array of events

Question

I've retrieved data from 2 different shared Google Calendars, and stored the data in an array. I need to sort the data into a sectioned UITableView, sorted by date. Heres my code: CalendarModel.h ``` #import "JSONModel.h" #import "Time.h" @interface CalendarModel : JSONModel @property (strong, nonatomic) NSString* title; @property (strong, nonatomic) NSArray<Time>* time; @end ``` CalendarModel.m ``` #import "CalendarModel.h" @implementation CalendarModel +(JSONKeyMapper*)keyMapper { return [[JSONKeyMapper alloc] initWithDictionary:@{ @"gd$when": @"time", @"title.$t": @"title", }]; } @end ``` Time.h ``` #import "JSONModel.h" @protocol Time @end @interface Time : JSONModel @property (strong, nonatomic) NSString* startTime; @property (strong, nonatomic) NSString* endTime; @end ``` Time.m does nothing, as it's handled by JSONModel SportsViewController.m ``` #import "SportsViewController.h" #import "JSONModelLib.h" #import "CalendarModel.h" #import "Time.h" #import "JSONValueTransformer.h"…

Accepted Answer

First group all your events - you'll have to take care of variable scoping (I'm using days and groupedEvents locally but you'll have to declare those as ivars/properties)

```
    NSMutableArray *days = [NSMutableArray array];
    NSMutableDictionary *groupedEvents = [NSMutableDictionary dictionary];

- (void)groupEventsIntoDays
{
    for (CalendarModel *event in _events)
    {
        NSString *dato = [[event.time objectAtIndex:0] startTime];
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        formatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ss.SSSzzz";
        NSDate *gmtDate = [formatter dateFromString: dato];

if (![days containsObject:gmtDate])
        {
            [days addObject:gmtDate];
            [groupedEvents setObject:[NSMutableArray arrayWithObject:event] forKey:gmtDate];
        }
        else
        {
            [((NSMutableArray*)[groupedEvents objectForKey:gmtDate]) addObject:event];
        }
    }

days = [[days sortedArrayUsingSelector:@selector(compare:)] mutableCopy];
}
```

Section headers:

```
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *header = [[UIView alloc] initWithFrame:CGRectMake(0,0,tableView.frame.size.width, 30)];
    UILabel *headerLabel = [[UILabel alloc] initWithFrame:header.bounds];
    [header addSubview:headerLabel];

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    formatter.dateFormat = @"dd-MM-yyyy HH:mm";
    NSString *dateAsString = [formatter stringFromDate:[days objectAtIndex:section]];

[headerLabel setText:dateAsString];

return header;
}
```

I only touched the first two lines in your cellForRow - you can modify the rest as needed for display/formatting:

```
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

NSDate *date = [days objectAtIndex:indexPath.section];
    CalendarModel *event = [((NSMutableArray*)[groupedEvents objectForKey:date]) objectAtIndex:indexPath.row];

NSString *dato = [[event.time objectAtIndex:0] startTime];
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    formatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ss.SSSzzz";
    NSDate *gmtDate = [formatter dateFromString: dato];
    formatter.dateFormat = @"dd-MM-yyyy HH:mm";
    dato = [formatter stringFromDate:gmtDate];

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"SportCell" forIndexPath:indexPath];
    cell.textLabel.text = [NSString stringWithFormat:@"%@",
                           event.title
                           ];
    cell.detailTextLabel.text = dato;

return cell;
}
```

Sort UITableView into sections by date from Array of events

Solution

Problem