Order an Array/Dictionary in objective c

Question

I am trying a little project where I get the current location coordinates, then by the current location I find coffee shops nearby and display them in a UITableView. So far I have managed to load the JSON script with the information, parse it into a dictionary, and display it in the UITableView. What I want to do now is try to order the information by 'distance' or by 'name' (alphabetically). How can I do that? Here is some code to show what I have done so far.

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{
if (!self.didFindLocation) {
    self.didFindLocation = YES;
    [self.locationManager stopUpdatingLocation];
}

NSMutableArray *resultArray = [[NSMutableArray alloc] init];
CLLocation *crnLoc = [locations lastObject];
NSString *latitudeString = [NSString stringWithFormat:@"%.10f",crnLoc.coordinate.latitude];
NSString *longitudeString = [NSString stringWithFormat:@"%.10f",crnLoc.coordinate.longitude];

NSString *urlString = [NSString stringWithFormat:@"https://api.foursquare.com/v2/venues/search?client_id=ACAO2JPKM1MXHQJCK45IIFKRFR2ZVL0QASMCBCG5NPJQWF2G&client_secret=YZCKUYJ1WHUV2QICBXUBEILZI1DMPUIDP5SHV043O04FKBHL&ll=%@,%@&query=coffee&v=20140806&m=foursquare", latitudeString, longitudeString];
NSURL *url = [NSURL URLWithString:urlString];

NSData *jsonData = [NSData dataWithContentsOfURL:url];
NSError *error = nil;
NSDictionary *dataDictionary = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];

NSDictionary *responseDictionary = [dataDictionary objectForKey:@"response"];
NSDictionary *venueDictionary = [responseDictionary objectForKey:@"venues"];

for (NSDictionary *dict in venueDictionary) {
    NSString *name = [dict objectForKey:@"name"];
    NSDictionary *locationDictionary = [dict objectForKey:@"location"];

    NSString *address = [NSString stringWithFormat: @"%@", [locationDictionary objectForKey:@"address"]];
    if (address == nil) {
        address = @"No address provided";
    }

    NSString *distance = [NSString stringWithFormat: @"%@", [locationDictionary objectForKey:@"distance"]];
    if (distance == nil) {
        distance = @"No coordinates provided";
    }

    NSLog(@"Name: %@ Address: %@  distance: %@", name, address, distance);

    CoffeeStore *store = [[CoffeeStore alloc] initWithName:name address:address distance:distance];

    [resultArray addObject:store];
}

self.storeArray = resultArray;
[self.tableView reloadData]; }

and

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

CoffeeStore *selectedStore = self.storeArray[indexPath.row];
cell.textLabel.text = selectedStore.name;
cell.detailTextLabel.text = selectedStore.distanceString;

return cell;

}

Start By Checking this out : http://stackoverflow.com/questions/805547/how-to-sort-an-nsmutablearray-with-custom-objects-in-it — Ríomhaire, Feb 12 '15 at 00:16
Also, the `NSData` method `dataWithContentsOfURL` is synchronous and I think you're running this on the main thread. You really need to move that onto a background thread & then grab the main thread again after you get your data. — AdamPro13, Feb 12 '15 at 00:27

score 0 · Accepted Answer · answered Feb 12 '15 at 00:30

0

Your resultArray contains an array of CoffeeStore objects, which have a distance given to their init method. You need to sort the array based on distance, before you call reloaddata. Hopefully those objects have a distance property and you can sort by that property, like this:

NSSortDescriptor *distanceDesc = [NSSortDescriptor sortDescriptorWithKey:@"distance" ascending:YES];

self.storeArray = [resultArray sortedArrayUsingDescriptors:@[distanceDesc]];

answered Feb 12 '15 at 00:30

joe77

211
2
5

So I am getting *Terminating app due to uncaught exception 'NSUnknownKeyException*. How do I define a distance key? do I need to do that in my CoffeeStore class or my main tableview class? – Tal Zamirly Feb 12 '15 at 01:13
You need to add a `distance` property to your CoffeeStore class – joe77 Feb 12 '15 at 01:22
I got one, thats how I add the information to the object. EG: CoffeeStore *store = [[CoffeeStore alloc] initWithName:name address:address distance:distance]; – Tal Zamirly Feb 12 '15 at 01:22
It sounds like you *do not* have one, that why you get the exception. You need a property declared similar to this in the class: `@property (nonatomic,assign) CLLocationDistance distance;` – joe77 Feb 12 '15 at 01:26
Okay sorted, thank you very much – Tal Zamirly Feb 12 '15 at 01:29

Order an Array/Dictionary in objective c

1 Answers1